Staff directory

Arben Merkoçi Hyka

ICREA Research Professor and Group Leader
arben.merkoci(ELIMINAR)@icn2.cat
Nanobioelectronics and Biosensors

Publications

2017

  • Biosensors for plant pathogen detection

    Khater M., de la Escosura-Muñiz A., Merkoçi A. Biosensors and Bioelectronics; 93: 72 - 86. 2017. 10.1016/j.bios.2016.09.091.

    Infectious plant diseases are caused by pathogenic microorganisms such as fungi, bacteria, viruses, viroids, phytoplasma and nematodes. Worldwide, plant pathogen infections are among main factors limiting crop productivity and increasing economic losses. Plant pathogen detection is important as first step to manage a plant disease in greenhouses, field conditions and at the country boarders. Current immunological techniques used to detect pathogens in plant include enzyme-linked immunosorbent assays (ELISA) and direct tissue blot immunoassays (DTBIA). DNA-based techniques such as polymerase chain reaction (PCR), real time PCR (RT-PCR) and dot blot hybridization have also been proposed for pathogen identification and detection. However these methodologies are time-consuming and require complex instruments, being not suitable for in-situ analysis. Consequently, there is strong interest for developing new biosensing systems for early detection of plant diseases with high sensitivity and specificity at the point-of-care. In this context, we revise here the recent advancement in the development of advantageous biosensing systems for plant pathogen detection based on both antibody and DNA receptors. The use of different nanomaterials such as nanochannels and metallic nanoparticles for the development of innovative and sensitive biosensing systems for the detection of pathogens (i.e. bacteria and viruses) at the point-of-care is also shown. Plastic and paper-based platforms have been used for this purpose, offering cheap and easy-to-use really integrated sensing systems for rapid on-site detection. Beside devices developed at research and development level a brief revision of commercially available kits is also included in this review. © 2016 Elsevier B.V.


  • Electrochemically reduced graphene and iridium oxide nanoparticles for inhibition-based angiotensin-converting enzyme inhibitor detection

    Kurbanoglu S., Rivas L., Ozkan S.A., Merkoçi A. Biosensors and Bioelectronics; 88: 122 - 129. 2017. 10.1016/j.bios.2016.07.109.

    In this work, a novel biosensor based on electrochemically reduced graphene oxide and iridium oxide nanoparticles for the detection of angiotensin-converting enzyme inhibitor drug, captopril, is presented. For the preparation of the biosensor, tyrosinase is immobilized onto screen printed electrode by using 1-Ethyl-3-(3-dimethylaminopropyl)-carbodiimide and N-Hydroxysuccinimide coupling reagents, in electrochemically reduced graphene oxide and iridium oxide nanoparticles matrix. Biosensor response is characterized towards catechol, in terms of graphene oxide concentration, number of cycles to reduce graphene oxide, volume of iridium oxide nanoparticles and tyrosinase solution. The designed biosensor is used to inhibit tyrosinase activity by Captopril, which is generally used to treat congestive heart failure. It is an angiotensin-converting enzyme inhibitor that operates via chelating copper at the active site of tyrosinase and thioquinone formation. The captopril detections using both inhibition ways are very sensitive with low limits of detection: 0.019 µM and 0.008 µM for chelating copper at the active site of tyrosinase and thioquinone formation, respectively. The proposed methods have been successfully applied in captopril determination in spiked human serum and pharmaceutical dosage forms with acceptable recovery values. © 2016 Elsevier B.V.


  • Graphene-Based Biosensors: Going Simple

    Morales-Narváez E., Baptista-Pires L., Zamora-Gálvez A., Merkoçi A. Advanced Materials; 29 (7, 1604905) 2017. 10.1002/adma.201604905.

    The main properties of graphene derivatives facilitating optical and electrical biosensing platforms are discussed, along with how the integration of graphene derivatives, plastic, and paper can lead to innovative devices in order to simplify biosensing technology and manufacture easy-to-use, yet powerful electrical or optical biosensors. Some crucial issues to be overcome in order to bring graphene-based biosensors to the market are also underscored. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim


  • Graphene-based hybrid for enantioselective sensing applications

    Zor E., Morales-Narváez E., Alpaydin S., Bingol H., Ersoz M., Merkoçi A. Biosensors and Bioelectronics; 87: 410 - 416. 2017. 10.1016/j.bios.2016.08.074.

    Chirality is a major field of research of chemical biology and is essential in pharmacology. Accordingly, approaches for distinguishing between different chiral forms of a compound are of great interest. We report on an efficient and generic enantioselective sensor that is achieved by coupling reduced graphene oxide with γ-cyclodextrin (rGO/γ-CD). The enantioselective sensing capability of the resulting structure was operated in both electrical and optical mode for of tryptophan enantiomers (D-/L-Trp). In this sense, voltammetric and photoluminescence measurements were conducted and the experimental results were compared to molecular docking method. We gain insight into the occurring recognition mechanism with selectivity toward D- and L-Trp as shown in voltammetric, photoluminescence and molecular docking responses. As an enantioselective solid phase on an electrochemical transducer, thanks to the different dimensional interaction of enantiomers with hybrid material, a discrepancy occurs in the Gibbs free energy leading to a difference in oxidation peak potential as observed in electrochemical measurements. The optical sensing principle is based on the energy transfer phenomenon that occurs between photoexcited D-/L-Trp enantiomers and rGO/γ-CD giving rise to an enantioselective photoluminescence quenching due to the tendency of chiral enantiomers to form complexes with γ-CD in different molecular orientations as demonstrated by molecular docking studies. The approach, which is the first demonstration of applicability of molecular docking to show both enantioselective electrochemical and photoluminescence quenching capabilities of a graphene-related hybrid material, is truly new and may have broad interest in combination of experimental and computational methods for enantiosensing of chiral molecules. © 2016 Elsevier B.V.


  • Rapid on-chip apoptosis assay on human carcinoma cells based on annexin-V/quantum dot probes

    Montón H., Medina-Sánchez M., Soler J.A., Chałupniak A., Nogués C., Merkoçi A. Biosensors and Bioelectronics; 94: 408 - 414. 2017. 10.1016/j.bios.2017.03.034.

    Despite all the efforts made over years to study the cancer expression and the metastasis event, there is not a clear understanding of its origins and effective treatment. Therefore, more specialized and rapid techniques are required for studying cell behaviour under different drug-based treatments. Here we present a quantum dot signalling-based cell assay carried out in a segmental microfluidic device that allows studying the effect of anti-cancer drugs in cultured cell lines by monitoring phosphatidylserine translocation that occurs in early apoptosis. The developed platform combines the automatic generation of a drug gradient concentration, allowing exposure of cancer cells to different doses, and the immunolabeling of the apoptotic cells using quantum dot reporters. Thereby a complete cell-based assay for efficient drug screening is performed showing a clear correlation between drug dose and amount of cells undergoing apoptosis. © 2017 Elsevier B.V.


  • Toward integrated detection and graphene-based removal of contaminants in a lab-on-a-chip platform

    Chałupniak A., Merkoçi A. Nano Research; : 1 - 15. 2017. 10.1007/s12274-016-1420-3.

    A novel, miniaturized microfluidic platform was developed for the simultaneous detection and removal of polybrominated diphenyl ethers (PBDEs). The platform consists of a polydimethylsiloxane (PDMS) microfluidic chip for an immunoreaction step, a PDMS chip with an integrated screen-printed electrode (SPCE) for detection, and a PDMS-reduced graphene oxide (rGO) chip for physical adsorption and subsequent removal of PBDE residues. The detection was based on competitive immunoassay-linked binding between PBDE and PBDE modified with horseradish peroxidase (HRP-PBDE) followed by the monitoring of enzymatic oxidation of o-aminophenol (o-AP) using square wave anodic stripping voltammetry (SW-ASV). PBDE was detected with good sensitivity and a limit of detection similar to that obtained with a commercial colorimetric test (0.018 ppb), but with the advantage of using lower reagent volumes and a reduced analysis time. The use of microfluidic chips also provides improved linearity and a better reproducibility in comparison to those obtained with batch-based measurements using screen-printed electrodes. In order to design a detection system suitable for toxic compounds such as PBDEs, a reduced graphene oxide–PDMS composite was developed and optimized to obtain increased adsorption (based on both the hydrophobicity and π–π stacking between rGO and PBDE molecules) compared to those of non-modified PDMS. To the best of our knowledge, this is the first demonstration of electrochemical detection of flame retardants and a novel application of the rGO-PDMS composite in a biosensing system. This system can be easily applied to detect any analyte using the appropriate immunoassay and it supports operation in complex matrices such as seawater. [Figure not available: see fulltext.] © 2017 Tsinghua University Press and Springer-Verlag Berlin Heidelberg


2016

  • Bio(Sensing) devices based on ferrocene–functionalized graphene and carbon nanotubes

    Rabti A., Raouafi N., Merkoçi A. Carbon; 108: 481 - 514. 2016. 10.1016/j.carbon.2016.07.043. IF: 6.198

    Both carbon nanotubes (CNTs) and graphene are important pillars in the ongoing efforts to devise new applications in nanotechnology. One of their most promising applications is building devices such as sensors and biosensors, which is important step for the development of personalized medical healthcare devices. Mediators are usually used and sought to modify the physicochemical properties of these materials. In this review, we highlight the importance of the functionalization of CNT and graphene derivatives with redox molecules taking ferrocene derivatives as a model molecule. The employed techniques during (bio)sensing measurements using various functionalization strategies are also described. In addition, we discuss various aspects related to the applications of ferrocene–modified CNTs and graphene in electrochemical sensors and biosensors with a focus on the explanation of both CNTs/graphene and ferrocene contributions in the catalytic systems, which in turn enhance the analytical performance of the (bio)sensing devices. © 2016 Elsevier Ltd


  • Control of Electron-transfer in Immunonanosensors by Using Polyclonal and Monoclonal Antibodies

    Mars A., Parolo C., de la Escosura-Muñiz A., Raouafi N., Merkoçi A. Electroanalysis; 28 (8): 1795 - 1802. 2016. 10.1002/elan.201500646. IF: 2.471

    The design and operation of biosensors is not trivial. For instance, variation in the output signal during monitoring of analytes can not usually be controlled. Hence, if such control were possible, and could be triggered on demand, it would greatly facilitate system design and operation. Herein, we report the design of two types of voltamperometric immunosensors, in which the magnitude of the current output signal (differential pulse voltammetry [DPV]) can be increased or decreased as needed. The designed systems use monoclonal and polyclonal anti-human IgG antibodies, conjugated to monopodal ferrocene-modified gold nanoparticles that are casted onto screen-printed carbon electrodes (Ab/mFcL/AuNPs/SPCEs). Upon addition of human IgG as antigen, the systems exhibit opposite responses according to the Ab: the current decreases when monoclonal Ab is used, whereas it increases when polyclonal Ab is used. We attributed the former response to inhibition of electron-transfer (due to the formation of a protein layer), and the latter response, to a global increase in electron transfer (induced by the aggregation of gold nanoparticles). These effects were confirmed by studying a custom-made lipoic acid-based bipodal ligand, which confirmed that the increase in current is effectively induced by the aggregation of the modified nanoparticles (pAb/mFcL/AuNPs). Both sensors have large dynamic ranges, although the pAb-based one was found to be 3.3-times more sensitive. Tests of selectivity and specificity for ovalbumin, α-lactalbumin and serum bovine albumin showed that the immunosensors are highly selective and specific, even in the presence of up to 1000-fold levels of potentially competitive proteins. The limit of detection for human IgG using the pAb/mFcL/AuNP bioconjugate was estimated to be 0.85 ng/mL. The pAb/mFcL/AuNPs-based biosensor has used to determine amounts of human IgG in real sample. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim


  • Detection of parathyroid hormone-like hormone in cancer cell cultures by gold nanoparticle-based lateral flow immunoassays

    Chamorro-Garcia A., de la Escosura-Muñiz A., Espinoza-Castañeda M., Rodriguez-Hernandez C.J., de Torres C., Merkoçi A. Nanomedicine: Nanotechnology, Biology, and Medicine; 12 (1): 53 - 61. 2016. 10.1016/j.nano.2015.09.012. IF: 5.671

    Parathyroid hormone-like hormone (PTHLH) exerts relevant roles in progression and dissemination of several tumors. However, factors influencing its production and secretion have not been fully characterized. The main limitation is the lack of specific, sensitive and widely available techniques to detect and quantify PTHLH. We have developed a lateral flow immunoassay using gold nanoparticles label for the fast and easy detection of PTHLH in lysates and culture media of three human cell lines (HaCaT, LA-N-1, SK-N-AS). Levels in culture media and lysates ranged from 11 to 20 ng/mL and 0.66 to 0.87 μg/mL respectively. Results for HaCaT are in agreement to the previously reported, whereas LA-N-1 and SK-N-AS have been evaluated for the first time. The system also exhibits good performance in human serum samples. This methodology represents a helpful tool for future in vitro and in vivo studies of mechanisms involved in PTHLH production as well as for diagnostics. From the Clinical Editor: Parathyroid Hormone-like Hormone (PTHLH) is known to be secreted by some tumors. However, the detection of this peptide remains difficult. The authors here described their technique of using gold nanoparticles as label for the detection of PTHLH by Lateral-flow immunoassays (LFIAs). The positive results may also point a way to using the same technique for the rapid determination of other relevant cancer proteins. © 2015 Elsevier Inc.


  • Emerging Nanomaterials for Analytical Detection

    Alarcon-Angeles G., Álvarez-Romero G.A., Merkoçi A. Comprehensive Analytical Chemistry; 74: 195 - 246. 2016. 10.1016/bs.coac.2016.03.022. IF: 0.000

    This chapter revises the recent trends in the use and applications of nanomaterials (NMs) in analytical detections with special interest in food quality control. The most important NMs such as gold nanoparticles, quantum dots, carbon-related nanomaterials and their properties are introduced. We show how analytical science is taking advantage of such materials to either develop new analytical methods or improve the existing technologies. Biosensing, in both batch and lab-on-a-chip formats, is one of the most important analytical technologies that is in the forefront of such interesting applications. The use of these materials in some conventional analytical techniques such as chromatography between others also is discussed. Examples related to such NMs application in real food samples with interest for quality control as well as detection of various interesting compounds such as glucose, amino acids, DNA (normally present in food) or other species that are usually of interest to be detected for safety reasons (bacteria, toxins) are discussed. Aspects related to the improvements of analytical performance in terms of detection limits, stability, selectivity, etc. using various NMs and detection technologies also are discussed. © 2016 Elsevier B.V.


  • Enhanced detection of quantum dots labeled protein by simultaneous bismuth electrodeposition into microfluidic channel

    Medina-Sánchez M., Miserere S., Cadevall M., Merkoçi A. Electrophoresis; 37 (3): 432 - 437. 2016. 10.1002/elps.201500288. IF: 2.482

    In this study, we propose an electrochemical immunoassay into a disposable microfluidic platform, using quantum dots (QDs) as labels and their enhanced detection using bismuth as an alternative to mercury electrodes. CdSe@ZnS QDs were used to tag human IgG as a model protein and detected through highly sensitive stripping voltammetry of the dissolved metallic component (cadmium in our case). The modification of the screen printed carbon electrodes (SPCEs) was done by a simple electrodeposition of bismuth that was previously mixed with the sample containing QDs. A magneto-immunosandwich assay was performed using a micromixer. A magnet placed at its outlet in order to capture the magnetic beads used as solid support for the immunoassay. SPCEs were integrated at the end of the channel as detector. Different parameters such as bismuth concentration, flow rate, and incubation times, were optimized. The LOD for HIgG in presence of bismuth was 3.5 ng/mL with a RSD of 13.2%. This LOD was about 3.3-fold lower than the one obtained without bismuth. Furthermore, the sensitivity of the system was increased 100-fold respect to experiments carried out with classical screen-printed electrodes, both in presence of bismuth. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


  • Ferrocene-functionalized graphene electrode for biosensing applications

    Rabti A., Mayorga-Martinez C.C., Baptista-Pires L., Raouafi N., Merkoçi A. Analytica Chimica Acta; 926: 28 - 35. 2016. 10.1016/j.aca.2016.04.010. IF: 4.712

    A novel ferrocene-functionalized reduced graphene oxide (rGO)-based electrode is proposed. It was fabricated by the drop casting of ferrocene-functionalized graphene onto polyester substrate as the working electrode integrated within screen-printed reference and counter electrodes. The ferrocene-functionalized rGO has been fully characterized using FTIR, XPS, contact angle measurements, SEM and TEM microscopy, and cyclic voltammetry. The XPS and EDX analysis showed the presence of Fe element related to the introduced ferrocene groups, which is confirmed by a clear CV signal at ca. 0.25 V vs. Ag/AgCl (0.1 KCl). Mediated redox catalysis of H2O2 and bio-functionalization with glucose oxidase for glucose detection were achieved by the bioelectrode providing a proof for potential biosensing applications. © 2016 Elsevier B.V.


  • Graphene-based Janus micromotors for the dynamic removal of pollutants

    Orozco J., Mercante L.A., Pol R., Merkoçi A. Journal of Materials Chemistry A; 4 (9): 3371 - 3378. 2016. 10.1039/c5ta09850e. IF: 8.262

    Persistent organic pollutants (POPs) are ubiquitous in the environment as a result of modern industrial processes. We present an effective POPs decontamination strategy based on their dynamic adsorption at the surface of reduced graphene oxide (rGO)-coated silica (SiO2)-Pt Janus magnetic micromotors for their appropriate final disposition. While the motors rapidly move in a contaminated solution, the adsorption of POPs efficiently takes place in a very short time. Characterization of the micromotors both from the materials and from the motion point of view was performed. Polybrominated diphenyl ethers (PBDEs) and 5-chloro-2-(2,4-dichlorophenoxy) phenol (triclosan) were chosen as model POPs and the removal of the contaminants was efficiently achieved. The rGO-coated micromotors demonstrated superior adsorbent properties with respect to their concomitant GO-coated micromotors, static rGO-coated particles and dynamic silica micromotors counterparts. The extent of decontamination was studied over the number of micromotors, whose magnetic properties were used for their collection from environmental samples. The adsorption properties were maintained for 4 cycles of micromotors reuse. The new rGO-coated SiO2 functional material-based micromotors showed outstanding capabilities towards the removal of POPs and their further disposition, opening up new possibilities for efficient environmental remediation of these hazardous compounds. © 2016 The Royal Society of Chemistry.


  • High-performance sensor based on copper oxide nanoparticles for dual detection of phenolic compounds and a pesticide

    Pino F., Mayorga-Martinez C.C., Merkoçi A. Electrochemistry Communications; 71: 33 - 37. 2016. 10.1016/j.elecom.2016.08.001. IF: 4.569

    The development of nanomaterials for use as bio-recognition elements is important in the evolution of biosensing systems. In the present article we present a sensing system based on copper oxide nanoparticles (CuO NPs) for the detection of phenolic compounds and pesticides. This sensor takes advantage of the interactions of CuO NPs with toxic compounds that in turn generate an electrochemical signal related to the concentration of the pollutants. © 2016


  • Hybrid self-assembled materials constituted by ferromagnetic nanoparticles and tannic acid: A theoretical and experimental investigation

    Santos A.F.M., Macedo L.J.A., Chaves M.H., Espinoza-Castañeda M., Merkoçi A., Limac F.D.C.A., Cantanhêde W. Journal of the Brazilian Chemical Society; 27 (4): 727 - 734. 2016. 10.5935/0103-5053.20150322. IF: 1.096

    Hybrid magnetite materials are interesting for both biomedical and catalytic applications due to their well-known biocompatibility, as well as their magnetic and electric properties. In this work we prepared Fe3 O4 nanoparticles (NPs) coated with tannic acid (TA), a natural polyphenol, through two different synthetic routes, aiming to understand the influence of TA in the synthesis step and contribute to the development of water-dispersible magnetic materials. The coating process was verified by information obtained from transmission electron microscopy (TEM), zeta-potential and Fourier transform infrared (FTIR) spectroscopy. The incorporation of TA after Fe3 O4 NPs production generated spherical NPs smaller than 10 nm, suggesting that TA plays a fundamental role in the nucleation and organization of Fe3 O4 NPs. Data from both density functional theory (DFT) and FTIR allowed us to infer that Fe3 O4 interacts mainly with the carbonyl groups of TA. Hybrid materials having improved water-dispersibility are very attractive for biomedical applications. ©2016 Sociedade Brasileira de Química.


  • Magnetic Bead/Gold Nanoparticle Double-Labeled Primers for Electrochemical Detection of Isothermal Amplified Leishmania DNA

    De La Escosura-Muñiz A., Baptista-Pires L., Serrano L., Altet L., Francino O., Sánchez A., Merkoçi A. Small; 12 (2): 205 - 213. 2016. 10.1002/smll.201502350. IF: 8.315

    A novel methodology for the isothermal amplification of Leishmania DNA using labeled primers combined with the advantages of magnetic purification/preconcentration and the use of gold nanoparticle (AuNP) tags for the sensitive electrochemical detection of such amplified DNA is developed. Primers labeled with AuNPs and magnetic beads (MBs) are used for the first time for the isothermal amplification reaction, being the amplified product ready for the electrochemical detection. The electrocatalytic activity of the AuNP tags toward the hydrogen evolution reaction allows the rapid quantification of the DNA on screen-printed carbon electrodes. Amplified products from the blood of dogs with Leishmania (positive samples) are discriminated from those of healthy dogs (blank samples). Quantitative studies demonstrate that the optimized method allows us to detect less than one parasite per microliter of blood (8 × 10-3 parasites in the isothermal amplification reaction). This pioneering approach is much more sensitive than traditional methods based on real-time polymerase chain reaction (PCR), and is also more rapid, cheap, and user-friendly. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


  • Microfluidic platform for environmental contaminants sensing and degradation based on boron-doped diamond electrodes

    Medina-Sánchez M., Mayorga-Martinez C.C., Watanabe T., Ivandini T.A., Honda Y., Pino F., Nakata A., Fujishima A., Einaga Y., Merkoçi A. Biosensors and Bioelectronics; 75: 365 - 374. 2016. 10.1016/j.bios.2015.08.058. IF: 7.476

    We have developed a lab-on-a-chip (LOC) platform for electrochemical detection and degradation of the pesticide atrazine (Atz). It is based on boron-doped diamond (BDD) electrodes and a competitive magneto-enzyme immunoassay (EIA) that enables high sensitivity. To detect the enzymatic reaction, we employed a BDD electrode modified with platinum nanoparticles (PtNPs), as a highly conductive catalytic transducer. Chronoamperometry revealed a limit of detection (LOD) of 3.5pM for atrazine, which, to the best of our knowledge, is one of the lowest value published to date. Finally, we degraded Atz in the same platform, using a bare BDD electrode that features remarkable corrosion stability, a wide potential window, and much higher O2 overvoltage as compared to conventional electrodes. These characteristics enable the electrode to produce a greater amount of HO• on the anode surface than do conventional electrodes and consequently, to destroy the pollutant more rapidly. Our new LOC platform might prove interesting as a smart system for detection and remediation of diverse pesticides and other contaminants. © 2015 Elsevier B.V.


  • Modulation of population density and size of silver nanoparticles embedded in bacterial cellulose: Via ammonia exposure: Visual detection of volatile compounds in a piece of plasmonic nanopaper

    Heli B., Morales-Narváez E., Golmohammadi H., Ajji A., Merkoçi A. Nanoscale; 8 (15): 7984 - 7991. 2016. 10.1039/c6nr00537c. IF: 7.760

    The localized surface plasmon resonance exhibited by noble metal nanoparticles can be sensitively tuned by varying their size and interparticle distances. We report that corrosive vapour (ammonia) exposure dramatically reduces the population density of silver nanoparticles (AgNPs) embedded within bacterial cellulose, leading to a larger distance between the remaining nanoparticles and a decrease in the UV-Vis absorbance associated with the AgNP plasmonic properties. We also found that the size distribution of AgNPs embedded in bacterial cellulose undergoes a reduction in the presence of volatile compounds released during food spoilage, modulating the studied nanoplasmonic properties. In fact, such a plasmonic nanopaper exhibits a change in colour from amber to light amber upon the explored corrosive vapour exposure and from amber to a grey or taupe colour upon fish or meat spoilage exposure. These phenomena are proposed as a simple visual detection of volatile compounds in a flexible, transparent, permeable and stable single-use nanoplasmonic membrane, which opens the way to innovative approaches and capabilities in gas sensing and smart packaging. © 2016 The Royal Society of Chemistry.


  • Molecularly Imprinted Polymer-Decorated Magnetite Nanoparticles for Selective Sulfonamide Detection

    Zamora-Gálvez A., Ait-Lahcen A., Mercante L.A., Morales-Narváez E., Amine A., Merkoçi A. Analytical Chemistry; 88 (7): 3578 - 3584. 2016. 10.1021/acs.analchem.5b04092. IF: 5.886

    Sulfonamides are known not only to be antimicrobial drugs that lead to antimicrobial resistance but also to be chemotherapeutic agents that may be allergenic and potentially carcinogenic, which represents a potentially hazardous compound once present in soil or water. Herein, a hybrid material based on molecularly imprinted polymer (MIP)-decorated magnetite nanoparticles for specific and label-free sulfonamide detection is reported. The composite has been characterized using different spectroscopic and imaging techniques. The magnetic properties of the composite are used to separate, preconcentrate, and manipulate the analyte which is selectively captured by the MIP onto the surface of the composite. Screen printed electrodes have been employed to monitor the impedance levels of the whole material, which is related to the amount of the captured analyte, via electrochemical impedance spectroscopy. This composite-based sensing system exhibits an extraordinary limit of detection of 1 × 10-12 mol L-1 (2.8 × 10-4 ppb) (S/N = 3), which is close to those obtained with liquid chromatography and mass spectrometry, and it was demonstrated to screen sulfamethoxazole in a complex matrix such as seawater, where according to the literature sulfonamides content is minimum compared with other environmental samples. © 2016 American Chemical Society.


  • Nanochannels for electrical biosensing

    de la Escosura-Muñiz A., Merkoçi A. TrAC - Trends in Analytical Chemistry; 79: 134 - 150. 2016. 10.1016/j.trac.2015.12.003. IF: 7.487

    This review shows the recent trends on the use of both single and array nanochannels for electrical biosensing applications. Some general considerations on the principles of the stochastic sensing, together with an overview about the common routes for nanochannels preparation before focusing on the applications for DNA, protein, virus, toxin and other analytes detection are given. Emerging materials used to obtain nanochannels, such as graphene and its analogues as well as novel systems based on the use of nanoparticles in combination with nanochannels are discussed. Aspects related to the analytical performance of the developed devices are also discussed. Finally prospects for future improvements and applications of this technology are included. © 2015 Elsevier B.V.


  • Paper-based sensors and assays: A success of the engineering design and the convergence of knowledge areas

    López-Marzo A.M., Merkoçi A. Lab on a Chip - Miniaturisation for Chemistry and Biology; 16 (17): 3150 - 3176. 2016. 10.1039/c6lc00737f. IF: 5.586

    This review shows the recent advances and state of the art in paper-based analytical devices (PADs) through the analysis of their integration with microfluidics and LOC micro- and nanotechnologies, electrochemical/optical detection and electronic devices as the convergence of various knowledge areas. The important role of the paper design/architecture in the improvement of the performance of sensor devices is discussed. The discussion is fundamentally based on μPADs as the new generation of paper-based (bio)sensors. Data about the scientific publication ranking of PADs, illustrating their increase as an experimental research topic in the past years, are supplied. In addition, an analysis of the simultaneous evolution of PADs in academic lab research and industrial commercialization highlighting the parallelism of the technological transfer from academia to industry is displayed. A general overview of the market behaviour, the leading industries in the sector and their commercialized devices is given. Finally, personal opinions of the authors about future perspectives and tendencies in the design and fabrication technology of PADs are disclosed. © 2016 The Royal Society of Chemistry.


  • Water activated graphene oxide transfer using wax printed membranes for fast patterning of a touch sensitive device

    Baptista-Pires L., Mayorga-Martínez C.C., Medina-Sánchez M., Montón H., Merkoçi A. ACS Nano; 10 (1): 853 - 860. 2016. 10.1021/acsnano.5b05963. IF: 13.334

    We demonstrate a graphene oxide printing technology using wax printed membranes for the fast patterning and water activation transfer using pressure based mechanisms. The wax printed membranes have 50 μm resolution, longtime stability and infinite shaping capability. The use of these membranes complemented with the vacuum filtration of graphene oxide provides the control over the thickness. Our demonstration provides a solvent free methodology for printing graphene oxide devices in all shapes and all substrates using the roll-toroll automatized mechanism present in the wax printing machine. Graphene oxide was transferred over a wide variety of substrates as textile or PET in between others. Finally, we developed a touch switch sensing device integrated in a LED electronic circuit. © 2015 American Chemical Society.


2015

  • Alzheimer's disease biomarkers detection in human samples by efficient capturing through porous magnetic microspheres and labelling with electrocatalytic gold nanoparticles

    de la Escosura-Muñiz A., Plichta Z., Horák D., Merkoçi A. Biosensors and Bioelectronics; 67: 162 - 169. 2015. 10.1016/j.bios.2014.07.086. IF: 6.409

    A nanobiosensor based on the use of porous magnetic microspheres (PMM) as efficient capturing/pre-concentrating platform is presented for detection of Alzheimer's disease (AD) biomarkers. These PMMs prepared by a multistep swelling polymerization combined with iron oxide precipitation afford carboxyl functional groups suitable for immobilization of antibodies on the particle surface allowing an enhanced efficiency in the capturing of AD biomarkers from human serum samples. The AD biomarkers signaling is produced by gold nanoparticle (AuNP) tags monitored through their electrocatalytic effect towards hydrogen evolution reaction (HER). Novel properties of PMMs in terms of high functionality and high active area available for enhanced catalytic activity of the captured AuNPs electrocatalytic tags are exploited for the first time. A thorough characterization by scanning transmission electron microscope in high angle annular dark field mode (STEM-HAADF) demonstrates the enhanced ability of PMMs to capture a higher quantity of analyte and consequently of electrocatalytic label, when compared with commercially available microspheres. The optimized and characterized PMMs are also applied for the first time for the detection of beta amyloid and ApoE at clinical relevant levels in cerebrospinal fluid (CSF), serum and plasma samples of patients suffering from AD. © 2014 Elsevier B.V.


  • An iridium oxide nanoparticle and polythionine thin film based platform for sensitive Leishmania DNA detection

    Mayorga-Martinez C.C., Chamorro-García A., Serrano L., Rivas L., Quesada-Gonzalez D., Altet L., Francino O., Sánchez A., Merkoçi A. Journal of Materials Chemistry B; 3 (26): 5166 - 5171. 2015. 10.1039/c5tb00545k. IF: 4.726

    An impedimetric label-free genosensor for high sensitive DNA detection is developed. This system is based on a screen-printed carbon electrode modified with the thionine layer and iridium oxide nanoparticles (IrO2 NP). An aminated oligonucleotide probe is immobilized on the IrO2 NP/polythionine modified electrode and ethanolamine was used as a blocking agent. Different diluted PCR amplified DNA samples have been detected. The selectivity and reproducibility of this system are studied and the system was highly reproducible with RSD ≈ 15% and sensitive enough while using 2% of ethanolamine during the blocking step employed for genosensor preparation. © The Royal Society of Chemistry.


  • Annexin-V/quantum dot probes for multimodal apoptosis monitoring in living cells: Improving bioanalysis using electrochemistry

    Montón H., Parolo C., Aranda-Ramos A., Merkoçi A., Nogués C. Nanoscale; 7 (9): 4097 - 4104. 2015. 10.1039/c4nr07191c. IF: 7.394

    There is a great demand to develop novel techniques that allow useful and complete monitoring of apoptosis, which is a key factor of several diseases and a target for drug development. Here, we present the use of a novel dual electrochemical/optical label for the detection and study of apoptosis. We combined the specificity of Annexin-V for phosphatidylserine, a phospholipid expressed in the outer membrane of apoptotic cells, with the optical and electrochemical properties of quantum dots to create a more efficient label. Using this conjugate we addressed three important issues: (i) we made the labeling of apoptotic cells faster (30 min) and easier; (ii) we fully characterized the samples by common cell biological techniques (confocal laser scanning microscopy, scanning electron microscopy and flow cytometry); and (III) we developed a fast, cheap and quantitative electrochemical detection method for apoptotic cells with results in full agreement with those obtained by flow cytometry. This journal is © The Royal Society of Chemistry.


  • Antithyroid drug detection using an enzyme cascade blocking in a nanoparticle-based lab-on-a-chip system

    Kurbanoglu S., Mayorga-Martinez C.C., Medina-Sánchez M., Rivas L., Ozkan S.A., Merkoçi A. Biosensors and Bioelectronics; 67: 670 - 676. 2015. 10.1016/j.bios.2014.10.014. IF: 6.409

    A methimazole (MT) biosensor based on a nanocomposite of magnetic nanoparticles (MNPs) functionalized with iridium oxide nanoparticles (IrOx NPs) and tyrosinase (Tyr) immobilized onto screen printed electrode (SPE) by using a permanent magnet is presented. This system is evaluated in batch mode via chelating copper at the active site of tyrosinase and in flow mode by thioquinone formation. The MT detection in flow mode is achieved using a hybrid polydimethylsiloxane/polyester amperometric lab-on-a-chip (LOC) microsystem with an integrated SPE. Both systems are very sensitive with low limit of detection (LOD): 0.006. μM and 0.004. μM for batch and flow modes, respectively. Nevertheless, the flow mode has advantages such as its reusability, automation, low sample volume (6. μL), and fast response (20. s). Optimization and validation parameters such as enzyme-substrate amount, flow rate, inhibition conditions, repeatability and reproducibility of the biosensor have been performed. The proposed methods have been applied in MT detection in spiked human serum and pharmaceutical dosage forms. © 2014 Elsevier B.V.


  • Bismuth nanoparticles integration into heavy metal electrochemical stripping sensor

    Cadevall M., Ros J., Merkoçi A. Electrophoresis; 36 (16): 1872 - 1879. 2015. 10.1002/elps.201400609. IF: 3.028

    Between their many applications bismuth nanoparticles (BiNPs) are showing interest as pre-concentrators in heavy metals detection while being applied as working electrode modifiers used in electrochemical stripping analysis. From the different reported methods to synthesize BiNPs we are focused on the typical polyol method, largely used in these types of metallic and semi-metallic nanoparticles. This study presents the strategy for an easy control of the shape and size of BiNPs including nanocubes, nanosferes and triangular nanostructures. To improve the BiNP size and shape, different reducing agents (ethylene glycol or sodium hypophosphite) and stabilizers (polyvinyl pyrrolidone, PVP, in different amounts) have been studied. The efficiency of BiNPs for heavy metals analysis in terms of detection sensitivity while being used as modifiers of screen-printed carbon electrodes including the applicability of the developed device in real sea water samples is shown. A parallel study between the obtained nanoparticles and their performance in heavy metal sensing has been described in this communication. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


  • Eco-friendly electrochemical lab-on-paper for heavy metal detection

    Medina-Sánchez M., Cadevall M., Ros J., Merkoçi A. Analytical and Bioanalytical Chemistry; 2015. 10.1007/s00216-015-9022-6. IF: 3.436

    A disposable electrochemical lateral flow paper-based sensing device for heavy metal detection is proposed. The quantification of lead and cadmium in aqueous samples is demonstrated in a range from 10 to 100 ppb with a limit of detection of 7 and 11 ppb respectively. Moreover, the platform itself, which is made of paper, served as a sample pretreatment material due to its filtering properties. Real samples, especially in which the matrix is usually turbid and would in principle need a previous filtration, are successfully analyzed. This lab-on-paper device is simple, low cost, easy to fabricate, and portable, being a promising tool for new point-of-care applications in environmental monitoring, public health, and food safety. © 2015 Springer-Verlag Berlin Heidelberg


  • Electrochemical Impedance Spectroscopy (bio)sensing through hydrogen evolution reaction induced by gold nanoparticles

    Mayorga-Martinez C.C., Chamorro-Garcia A., Merkoçi A. Biosensors and Bioelectronics; 67: 53 - 58. 2015. 10.1016/j.bios.2014.05.066. IF: 6.409

    A new gold nanoparticle (AuNP) based detection strategy using Electrochemical Impedance Spectroscopy (EIS) through hydrogen evolution reaction (HER) is proposed. This EIS-HER method is used as an alternative to the conventional EIS based on [Fe(CN)6]3-/4- or [Ru(NH3)6]3+/2+ indicators. The proposed method is based on the HER induced by AuNPs. EIS measurements for different amounts of AuNP are registered and the charge transfer resistance (Rct) was found to correlate and be useful for their quantification. Moreover the effect of AuNP size on electrical properties of AuNPs for HER using this sensitive technique has been investigated. Different EIS-HER signals generated in the presence of AuNPs of different sizes (2, 5, 10, 15, 20, and 50nm) are observed, being the corresponding phenomena extendible to other nanoparticles and related catalytic reactions. This EIS-HER sensing technology is applied to a magneto-immunosandwich assay for the detection of a model protein (IgG) achieving improvements of the analytical performance in terms of a wide linear range (2-500ngmL-1) with a good limit of detection (LOD) of 0.31ngmL-1 and high sensitivity. Moreover, with this methodology a reduction of one order of magnitude in the LOD for IgG detection, compared with a chroamperometric technique normally used was achieved. © 2014 Elsevier B.V.


  • Graphene quantum dots-based photoluminescent sensor: A multifunctional composite for pesticide detection

    Zor E., Morales-Narváez E., Zamora-Gálvez A., Bingol H., Ersoz M., Merkoçi A. ACS Applied Materials and Interfaces; 7 (36): 20272 - 20279. 2015. 10.1021/acsami.5b05838. IF: 6.723

    Due to their size and difficulty to obtain, cost/effective biological or synthetic receptors (e.g., antibodies or aptamers, respectively), organic toxic compounds (e.g., less than 1 kDa) are generally challenging to detect using simple platforms such as biosensors. This study reports on the synthesis and characterization of a novel multifunctional composite material, magnetic silica beads/graphene quantum dots/molecularly imprinted polypyrrole (mSGP). mSGP is engineered to specifically and effectively capture and signal small molecules due to the synergy among chemical, magnetic, and optical properties combined with molecular imprinting of tributyltin (291 Da), a hazardous compound, selected as a model analyte. Magnetic and selective properties of the mSGP composite can be exploited to capture and preconcentrate the analyte onto its surface, and its photoluminescent graphene quantum dots, which are quenched upon analyte recognition, are used to interrogate the presence of the contaminant. This multifunctional material enables a rapid, simple and sensitive platform for small molecule detection, even in complex mediums such as seawater, without any sample treatment. © 2015 American Chemical Society.


  • Highly sensitive and rapid determination of Escherichia coli O157: H7 in minced beef and water using electrocatalytic gold nanoparticle tags

    Hassan A.R.H.A.A., de la Escosura-Muñiz A., Merkoçi A. Biosensors and Bioelectronics; 67: 511 - 515. 2015. 10.1016/j.bios.2014.09.019. IF: 6.409

    A simple, highly sensitive and specific immunosensing assay for rapid detection and quantification of Escherichia coli O157:H7 in meat and water samples based on the electrocatalytic properties of gold nanoparticles (AuNPs) towards hydrogen evolution reaction and superparamagnetic microbeads (MBs) as pre-concentration/purification platforms without the need of broth enrichment is developed for the first time. Minced beef and water samples inoculated with different concentrations of E. coli O157:H7 have been tested using anti-E. coli O157-magnetic beads conjugate (MBs-pECAb) as a capture platform and sandwiching afterwards with AuNPs modified with secondary antibodies (AuNPs-sECAb) and detected using chronoamperometric measurement with screen-printed carbon electrodes (SPCEs). Detection limits (LOD) of 148, 457 and 309CFU/mL were obtained in buffer solution, minced beef and tap water samples respectively, with a broad detection range of 102-105CFU/mL in all cases. Recoveries percentages after spiking of 5 different samples of both minced beef and tap water with 103 and 104CFU/mL were 94.7 and 90.4 (in beef) and 91.3 and 94.8% (in water), respectively. Specificity, reproducibility and comparison with a commercial lateral flow kit in terms of LOD and detection range were also studied showing clear advantages of the electrochemical method performance. The successful application of this AuNPs based technology in minced beef and tap water indicates the possibility of its using in various food items and other water resources. © 2014 Elsevier B.V.


  • In situ production of biofunctionalized few-layer defect-free microsheets of graphene

    Gravagnuolo A.M., Morales-Narváez E., Longobardi S., Da Silva E.T., Giardina P., Merkoçi A. Advanced Functional Materials; 25 (18): 2771 - 2779. 2015. 10.1002/adfm.201500016. IF: 11.805

    Biological interfacing of graphene has become crucial to improve its biocompatibility, dispersability, and selectivity. However, biofunctionalization of graphene without yielding defects in its sp2-carbon lattice is a major challenge. Here, a process is set out for biofunctionalized defect-free graphene synthesis through the liquid phase ultrasonic exfoliation of raw graphitic material assisted by the self-assembling fungal hydrophobin Vmh2. This protein (extracted from the edible fungus Pleurotus ostreatus) is endowed with peculiar physicochemical properties, exceptional stability, and versatility. The unique properties of Vmh2 and, above all, its superior hydrophobicity, and stability allow to obtain a highly concentrated (≈440-510 μg mL-1) and stable exfoliated material (ζ-potential, +40/+70 mV). In addition controlled centrifugation enables the selection of biofunctionalized few-layer defect-free micrographene flakes, as assessed by Raman spectroscopy, atomic force microscopy, scanning electron microscopy, and electrophoretic mobility. This biofunctionalized product represents a high value added material for the emerging applications of graphene in the biotechnological field such as sensing, nanomedicine, and bioelectronics technologies. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


  • Lab-in-a-syringe using gold nanoparticles for rapid immunosensing of protein biomarkers

    Nunes Pauli G.E., De La Escosura-Muñiz A., Parolo C., Helmuth Bechtold I., Merkoçi A. Lab on a Chip - Miniaturisation for Chemistry and Biology; 15 (2): 399 - 405. 2015. 10.1039/c4lc01123f. IF: 6.115

    We have developed a paper and gold nanoparticle (AuNP)-based lab-in-a-syringe (LIS) for immunosensing of biomarkers. This simple diagnostic device features simultaneous sampling and vertical-flow operation, which means that unlike typical immunosensors, it does not suffer from any delay between sampling and detection. It can handle large-volume, low-concentration samples for analysis in diverse applications (e.g. biomedical, environmental, food, etc.). Furthermore, its operating range for sample concentration can be tuned by simply changing the volume of the syringed sample, which enables on-demand limits of detection (LOD). The LIS contains two nitrocellulose pads: the conjugate pad (which captures the analyte) and the detection pad (which signals the presence of the captured analyte) both embedded into reusable plastic cartridges. We demonstrated its efficiency in detecting human IgG (HIgG) (LOD: 1.0 ng mL-1) and prostate-specific antigen (PSA) (spiked urine samples; LOD: 1.9 ng mL-1). In the field, the LIS can be used for complete on-site analysis or to obtain partially analyzed samples (AuNPs with captured analyte) for subsequent detailed testing in specialized laboratories. This journal is © The Royal Society of Chemistry 2015.


  • Label-free impedimetric aptasensor for ochratoxin-A detection using iridium oxide nanoparticles

    Rivas L., Mayorga-Martinez C.C., Quesada-González D., Zamora-Gálvez A., De La Escosura-Muñiz A., Merkoçi A. Analytical Chemistry; 87 (10): 5167 - 5172. 2015. 10.1021/acs.analchem.5b00890. IF: 5.636

    In this article, a novel aptasensor for ochratoxin A (OTA) detection based on a screen-printed carbon electrode (SPCE) modified with polythionine (PTH) and iridium oxide nanoparticles (IrO2 NPs) is presented. The electrotransducer surface is modified with an electropolymerized film of PTH followed by the assembly of IrO2 NPs on which the aminated aptamer selective to OTA is exchanged with the citrate ions surrounding IrO2 NPs via electrostatic interactions with the same surface. Electrochemical impedance spectroscopy (EIS) in the presence of the [Fe(CN)6]-3/-4 redox probe is employed to characterize each step in the aptasensor assay and also for label-free detection of OTA in a range between 0.01 and 100 nM, obtaining one of the lowest limits of detection reported so far for label-free impedimetric detection of OTA (14 pM; 5.65 ng/kg). The reported system also exhibits a high reproducibility, a good performance with a white wine sample, and an excellent specificity against another toxin present in such sample. © 2015 American Chemical Society.


  • Magnetic enzymatic platform for organophosphate pesticide detection using boron-doped diamond electrodes

    Pino F., Ivandini T.A., Nakata K., Fujishima A., Merkoçi A., Einaga Y. Analytical Sciences; 31 (10): 1061 - 1068. 2015. . IF: 1.394

    A simple and reliable enzymatic system for organophosporus pesticide detection was successfully developed, by exploiting the synergy between the magnetic beads collection capacity and the outstanding electrochemistry property of boron-doped diamond electrodes. The determination of an organophosphate pesticide, chlorpyrifos (CPF), was performed based on the inhibition system of the enzyme acetylcholinesterase bonded to magnetic beads through a biotin-streptavidin complex system. A better sensitivity was found for a system with magnetic beads in the concentration range of 10-9 to 10-5 M. The estimated limits of detection based on IC10 (10% acetylcholinesterase (AChE) inhibition) have been detected and optimized to be 5.7 × 10-10 M CPF. Spiked samples of water of Yokohama (Japan) have been measured to validate the efficiency of the enzymatic system. The results suggested that the use of magnetic beads to immobilize biomolecules or biosensing agents is suitable to maintain the superiority of BDD electrodes. © 2015 The Japan Society for Analytical Chemistry.


  • Micro and nanomotors in diagnostics

    Chałupniak A., Morales-Narváez E., Merkoçi A. Advanced Drug Delivery Reviews; 95: 104 - 116. 2015. 10.1016/j.addr.2015.09.004. IF: 15.038

    Synthetic micro/nanomotors are tiny devices than can be self-propelled or externally powered in the liquid phase by different types of energy source including but not limited to: catalytic, magnetic or acoustic. Showing a myriad of mechanical movements, building block materials, sizes, shapes and propulsion mechanisms micro/nanomotors are amenable to diagnostics and therapeutics. Herein we describe the most relevant micro/nanomotors, their fabrication pathways, propulsion strategies as well as in vivo and in vitro applications related with oligonucleotides, proteins, cells and tissues. We also discuss the main challenges in these applications such as the influence of complex media and toxicity issues as well as future perspectives. © 2015 Elsevier B.V.


  • Nanochannel array device operating through Prussian blue nanoparticles for sensitive label-free immunodetection of a cancer biomarker

    Espinoza-Castañeda M., Escosura-Muñiz A.D.L., Chamorro A., Torres C.D., Merkoçi A. Biosensors and Bioelectronics; 67: 107 - 114. 2015. 10.1016/j.bios.2014.07.039. IF: 6.409

    A novel nanochannel array (NC) device that operates through Prussian blue nanoparticles (PBNPs) as redox indicator for sensitive label free immunodetection of a cancer biomarker is presented. Stable and narrow-sized (around 4nm) PBNPs, protected by polyvinylpyrrolidone, exhibited a well-defined and reproducible redox behavior and were successfully applied for the voltammetric evaluation of the nanochannels (20nm pore sized) blockage due to the immunocomplex formation. The bigger size of the PBNPs compared with ionic indicators such as the [Fe(CN)6]4-/3- system leads to an increase in the steric effects hindering their diffusion toward the signaling electrode which in turn is transduced to an improvement of the detection limit from 200μgmL-1 to 34pg human IgGmL-1. This novel and effective PBNPs-NC technology for the detection of small proteins captured inside the nanochannels is successfully applied for the quantification of a cancer biomarker (parathyroid hormone-related protein, PTHrP) in a real clinical scenario such as cell culture medium. The achieved label-free detection of PTHrP at levels of 50ngmL-1 is with great interest to study relevant functions that this protein exerts in normal tissues and cancer. © 2014 Elsevier B.V.


  • Nanopaper as an Optical Sensing Platform

    Morales-Narváez E., Golmohammadi H., Naghdi T., Yousefi H., Kostiv U., Horák D., Pourreza N., Merkoçi A. ACS Nano; 9 (7): 7296 - 7305. 2015. 10.1021/acsnano.5b03097. IF: 12.881

    Bacterial cellulose nanopaper (BC) is a multifunctional material known for numerous desirable properties: sustainability, biocompatibility, biodegradability, optical transparency, thermal properties, flexibility, high mechanical strength, hydrophilicity, high porosity, broad chemical-modification capabilities and high surface area. Herein, we report various nanopaper-based optical sensing platforms and describe how they can be tuned, using nanomaterials, to exhibit plasmonic or photoluminescent properties that can be exploited for sensing applications. We also describe several nanopaper configurations, including cuvettes, plates and spots that we printed or punched on BC. The platforms include a colorimetric-based sensor based on nanopaper containing embedded silver and gold nanoparticles; a photoluminescent-based sensor, comprising CdSe@ZnS quantum dots conjugated to nanopaper; and a potential up-conversion sensing platform constructed from nanopaper functionalized with NaYF4:Yb3+@Er3+&SiO2 nanoparticles. We have explored modulation of the plasmonic or photoluminescent properties of these platforms using various model biologically relevant analytes. Moreover, we prove that BC is and advantageous preconcentration platform that facilitates the analysis of small volumes of optically active materials ∼4 μ). We are confident that these platforms will pave the way to optical (bio)sensors or theranostic devices that are simple, transparent, flexible, disposable, lightweight, miniaturized and perhaps wearable. © 2015 American Chemical Society.


  • Nanoparticle-based lateral flow biosensors

    Quesada-González D., Merkoçi A. Biosensors and Bioelectronics; 73: 47 - 63. 2015. 10.1016/j.bios.2015.05.050. IF: 6.409

    Lateral flow biosensors (LFBs) are paper-based devices which permit the performance of low-cost and fast diagnostics with good robustness, specificity, sensitivity and low limits of detection. The use of nanoparticles (NPs) as labels play an important role in the design and fabrication of a lateral flow strip (LFS). The choice of NPs and the corresponding detection method directly affect the performance of these devices. This review discusses aspects related to the application of different nanomaterials (e.g. gold nanoparticles, carbon nanotubes, quantum dots, up-converting phosphor technologies, and latex beads, between others) in LFBs. Moreover, different detection methods (colorimetric, fluorescent, electrochemical, magnetic, etc.) and signal enhancement strategies (affording secondary reactions or modifying the architecture of the LFS) as well as the use of devices such as smartphones to mediate the response of LFSs will be analyzed. © 2015 Elsevier B.V.


  • Nanoparticle/nanochannels-based electrochemical biosensors

    Espinoza-Castañeda M., de la Escosura-Munñiz A., Merkoçi A. NanoScience and Technology; 96: 205 - 223. 2015. 10.1007/978-3-319-14406-1_9. IF: 0.000

    The purpose of this chapter is to provide a general comprehensive overview on the latest trends in the development of nanoparticle/nanochannelsbased electrochemical biosensors. Given the importance of nanoparticles, some general considerations about their use in biosensors are given before focusing on nanochannels-based electrochemical biosensing systems. A detailed description of representative and recent works covering the main nanochannel arrays fabrication techniques and their application in electrochemical biosensing systems is also given. The combination of nanochannel array sensing capability with the known advantages of nanoparticles in immunosensing is shown as an ideal approach for the diagnostic of proteins and DNA. As conclusion, the integration of nanochannel arrays with electrochemical transducers (ex. screen-printed electrode) seems to be one of the most important challenges in the development of robust sensing devices that may bring electrochemical/nanochannel-based biosensing technology to the market. © Springer International Publishing Switzerland 2015.


  • Nanoparticles-based nanochannels assembled on a plastic flexible substrate for label-free immunosensing

    de la Escosura-Muñiz A., Espinoza-Castañeda M., Hasegawa M., Philippe L., Merkoçi A. Nano Research; 8 (4): 1180 - 1188. 2015. 10.1007/s12274-014-0598-5. IF: 7.010

    A novel, cheap, disposable and single-use nanoparticles-based nanochannel platform assembled on a flexible substrate for label-free immunosensing is presented. This sensing platform is formed by the dip-coating of a homogeneous and assembled monolayer of carboxylated polystyrene nanospheres (PS, 200 and 500 nm-sized) onto the working area of flexible screen-printed indium tin oxide/polyethylene terephthalate (ITO/PET) electrodes. The spaces between the self-assembled nanospheres generate well-ordered nanochannels, with inter-PS particles distances of around 65 and 24 nm respectively. The formed nanochannels are used for the effective immobilization of antibodies and subsequent protein detection based on the monitoring of [Fe(CN)6]4− flow through diffusion and the decrease in the differential pulse voltammetric signal upon immunocomplex formation. The obtained sensing system is nanochannel-size dependent and allows human immunoglobulin G (IgG) (chosen as a model analyte) to be detected at levels of 580 ng/mL. The system also exhibits an excellent specificity against other proteins present in real samples and shows good performance with a human urine sample. The developed device represents an integrated and simple biodetection system which overcomes many of the limitations of previously reported nanochannels-based approaches and can be extended in the future to several other immuno and DNA detection systems. © 2014, Tsinghua University Press and Springer-Verlag Berlin Heidelberg.


  • On-the-Spot Immobilization of Quantum Dots, Graphene Oxide, and Proteins via Hydrophobins

    Gravagnuolo A.M., Morales-Narváez E., Matos C.R.S., Longobardi S., Giardina P., Merkoçi A. Advanced Functional Materials; 25 (38): 6084 - 6092. 2015. 10.1002/adfm.201502837. IF: 11.805

    Class I hydrophobin Vmh2, a peculiar surface active and versatile fungal protein, is known to self-assemble into chemically stable amphiphilic films, to be able to change wettability of surfaces, and to strongly adsorb other proteins. Herein, a fast, highly homogeneous and efficient glass functionalization by spontaneous self-assembling of Vmh2 at liquid-solid interfaces is achieved (in 2 min). The Vmh2-coated glass slides are proven to immobilize not only proteins but also nanomaterials such as graphene oxide (GO) and quantum dots (QDs). As models, bovine serum albumin labeled with Alexa 555 fluorophore, anti-immunoglobulin G antibodies, and cadmium telluride QDs are patterned in a microarray fashion in order to demonstrate functionality, reproducibility, and versatility of the proposed substrate. Additionally, a GO layer is effectively and homogeneously self-assembled onto the studied functionalized surface. This approach offers a quick and simple alternative to immobilize nanomaterials and proteins, which is appealing for new bioanalytical and nanobioenabled applications. Immobilization of optically active nanomaterials and proteins (particularly, cadmium telluride quantum dots, graphene oxide, antibodies, and bovine serum albumin) on glass is achieved using a Janus-faced fungal protein, hydrophobin Vmh2, which is extracted from Pleurotus ostreatus. The proposed glass nanobiofunctionalization is fast, easily scalable, and environmental friendly, which is appealing for new bioanalytical and nanobioenabled applications. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


  • Photoluminescent Lateral-Flow Immunoassay Revealed by Graphene Oxide: Highly Sensitive Paper-Based Pathogen Detection

    Morales-Narváez E., Naghdi T., Zor E., Merkoçi A. Analytical Chemistry; 87 (16): 8573 - 8577. 2015. 10.1021/acs.analchem.5b02383. IF: 5.636

    A paper-based lateral flow immunoassay for pathogen detection that avoids the use of secondary antibodies and is revealed by the photoluminescence quenching ability of graphene oxide is reported. Escherichia coli has been selected as a model pathogen. The proposed device is able to display a highly specific and sensitive performance with a limit of detection of 10 CFU mL-1 in standard buffer and 100 CFU mL-1 in bottled water and milk. This low-cost disposable and easy-to-use device will prove valuable for portable and automated diagnostics applications. © 2015 American Chemical Society.


  • Triple lines gold nanoparticle-based lateral flow assay for enhanced and simultaneous detection of Leishmania DNA and endogenous control

    Rivas L., de la Escosura-Muñiz A., Serrano L., Altet L., Francino O., Sánchez A., Merkoçi A. Nano Research; 8 (11): 3704 - 3714. 2015. 10.1007/s12274-015-0870-3. IF: 7.010

    A novel triple lines lateral-flow assay (LFA) with enhanced sensitivity for the detection of Leishmania infantum DNA in dog blood samples was designed and successfully applied. The enhanced LFA methodology takes advantage of the gold nanoparticle tags (AuNPs) conjugated to polyclonal secondary antibodies, which recognize anti-FITC antibodies. The polyclonal nature of the secondary antibodies allows for multiple binding to primary antibodies, leading to enhanced AuNP plasmonics signal. Furthermore, endogenous control consisting of the amplified dog 18S rRNA gene was introduced to avoid false negatives. Using this strategy, 0.038 spiked Leishmania parasites per DNA amplification reaction (1 parasite/100 μL of DNA sample) were detected. Detection limit of LFA was found to be lower than that of the conventional techniques. In summary, our novel LFA design is a universal and simple sensing alternative that can be extended to several other biosensing scenarios. [Figure not available: see fulltext.] © 2015, Tsinghua University Press and Springer-Verlag Berlin Heidelberg.


2014

  • Alzheimer Disease Biomarker Detection Through Electrocatalytic Water Oxidation Induced by Iridium Oxide Nanoparticles

    Rivas, L.; de la Escosura-Muñiz, A.; Pons, J.; Merkoçi, A. Electroanalysis; 26 (6): 1287 - 1294. 2014. 10.1002/elan.201400027. IF: 2.502


  • An inkjet-printed field-effect transistor for label-free biosensing

    Medina-Sánchez, M.; Martínez-Domingo, C.; Ramon, E.; Merkoçi, A. Advanced Functional Materials; 24 (40): 6291 - 6302. 2014. 10.1002/adfm.201401180. IF: 10.439


  • An integrated phenol 'sensoremoval' microfluidic nanostructured platform

    Mayorga-Martinez, C.C.; Hlavata, L.; Miserere, S.; López-Marzo, A.; Labuda, J.; Pons, J.; Merkoçi, A. Biosensors and Bioelectronics; 55: 355 - 359. 2014. 10.1016/j.bios.2013.12.035. IF: 6.451


  • Electroanalysis-Based Clinical Diagnostics

    Merkoçi, A. Electroanalysis; 26 (6): 1110. 2014. 10.1002/elan.201410132. IF: 2.502


  • Electrocatalytic tuning of biosensing response through electrostatic or hydrophobic enzyme-graphene oxide interactions

    Baptista-Pires, L.; Pérez-López, B.; Mayorga-Martinez, C.C.; Morales-Narváez, E.; Domingo, N.; Esplandiu, M.J.; Alzina, F.; Torres, C.M.S.; Merkoçi, A. Biosensors and Bioelectronics; 61: 655 - 662. 2014. 10.1016/j.bios.2014.05.028. IF: 6.451


  • Electrochemical antibody-aptamer assay for VEGF cancer biomarker detection

    Ravalli A.; Marrazza G.; Rivas L.; De La Escosura-Muniz A.; Merkoci A. Lecture Notes in Electrical Engineering; 268 LNEE: 175 - 178. 2014. . IF: 0.000


  • Extremely fast and high Pb2+ removal capacity using a nanostructured hybrid material

    Lópezmarzo, A.M.; Pons, J.; Merkoçi, A. Journal of Materials Chemistry A; 2 (23): 8766 - 8772. 2014. 10.1039/c4ta00985a. IF: 0.000


  • Graphene/Silicon heterojunction schottky diode for vapors sensing using impedance spectroscopy

    Fattah, A.; Khatami, S.; Mayorga-Martinez, C.C.; Medina-Sánchez, M.; Baptista-Pires, L.; Merkoçi, A. Small; 10 (20): 4193 - 4199. 2014. 10.1002/smll.201400691. IF: 7.514


  • Improving sensitivity of gold nanoparticle-based lateral flow assays by using wax-printed pillars as delay barriers of microfluidics

    Rivas, L.; Medina-Sánchez, M.; De La Escosura-Muñiz, A.; Merkoçi, A. Lab on a Chip - Miniaturisation for Chemistry and Biology; 14 (22): 4406 - 4414. 2014. 10.1039/c4lc00972j. IF: 5.748


  • Iridium oxide nanoparticle induced dual catalytic/inhibition based detection of phenol and pesticide compounds

    Mayorga-Martinez, C.C.; Pino, F.; Kurbanoglu, S.; Rivas, L.; Ozkan, S.A.; Merkoçi, A. Journal of Materials Chemistry B; 2 (16): 2233 - 2239. 2014. 10.1039/c3tb21765e. IF: 0.000


  • Micromotor enhanced microarray technology for protein detection

    Morales-Narváez, E.; Guix, M.; Medina-Sánchez, M.; Mayorga-Martinez, C.C.; Merkoçi, A. Small; 10 (13): 2542 - 2548. 2014. 10.1002/smll.201303068. IF: 7.514


  • Nano/Micromotors in (Bio)chemical science applications

    Guix, M.; Mayorga-Martinez, C.C.; Merkoçi, A. Chemical Reviews; 114 (12): 6285 - 6322. 2014. 10.1021/cr400273r. IF: 45.661


  • On-chip magneto-immunoassay for Alzheimer's biomarker electrochemical detection by using quantum dots as labels

    Medina-Sánchez, M.; Miserere, S.; Morales-Narváez, E.; Merkoçi, A. Biosensors and Bioelectronics; 54: 279 - 284. 2014. 10.1016/j.bios.2013.10.069. IF: 6.451


  • Simple on-plastic/paper inkjet-printed solid- state Ag/AgCl pseudo-reference electrode

    da Silva, E.T. S. G.; Miserere, S.; Kubota, L.T.; Merkoçi, A. Analytical Chemistry; 86 (21): 10531 - 10534. 2014. . IF: 5.825


  • Supramolecular interaction of dopamine with ß-cyclodextrin: An experimental and theoretical electrochemical study

    Palomar-Pardavé, M.; Corona-Avendaño, S.; Romero-Romo, M.; Alarcón-Angeles, G.; Merkoçi, A.; Ramírez-Silva, M.T. Journal of Electroanalytical Chemistry; 717-718: 103 - 109. 2014. 10.1016/j.jelechem.2014.01.002. IF: 2.871


2013

  • All-integrated and highly sensitive paper based device with sample treatment platform for Cd2+ immunodetection in drinking/tap waters

    López Marzo, A.M.; Pons, J.; Blake, D.A.; Merkoçi, A. Analytical Chemistry; 85 (7): 3532 - 3538. 2013. 10.1021/ac3034536. IF: 5.695


  • Assembly of gold nanorods for highly sensitive detection of mercury ions

    Placido, T.; Comparelli, R.; Striccoli, M.; Agostiano, A.; Merkoci, A.; Curri, M.L. IEEE Sensors Journal; 13 (8): 2834 - 2841. 2013. 10.1109/JSEN.2013.2257738. IF: 1.475


  • Deprotonation mechanism and acidity constants in aqueous solution of flavonols: A combined experimental and theoretical study

    Álvarez-Diduk, R.; Ramírez-Silva, M.T.; Galano, A.; Merkoçi, A. Journal of Physical Chemistry B; 117 (41): 12347 - 12359. 2013. 10.1021/jp4049617. IF: 3.607


  • Design, preparation, and evaluation of a fixed-orientation antibody/gold-nanoparticle conjugate as an immunosensing label

    Parolo, C.; De La Escosura-Muñiz, A.; Polo, E.; Grazú, V.; De La Fuente, J.M.; Merkoçi, A. ACS applied materials & interfaces; 5 (21): 10753 - 10759. 2013. 10.1021/am4029153. IF: 5.008


  • Enhanced lateral flow immunoassay using gold nanoparticles loaded with enzymes

    Parolo, C.; de la Escosura-Muñiz, A.; Merkoçi, A. Biosensors and Bioelectronics; 40: 412 - 416. 2013. 10.1016/j.bios.2012.06.049. IF: 5.437


  • Gold nanoparticles decorated with a ferrocene derivative as a potential shift-based transducing system of interest for sensitive immunosensing

    Mars, A.; Parolo, C.; Raouafi, N.; Boujlel, K.; Merkoçi, A. Journal of Materials Chemistry B; 1 (23): 2951 - 2955. 2013. 10.1039/c3tb20503g. IF: 6.108


  • Graphene oxide as a pathogen-revealing agent: Sensing with a digital-like response

    Morales-Narváez, E.; Hassan, A.-R.; Merkoçi, A. Angewandte Chemie - International Edition; 52 (51): 13779 - 13783. 2013. 10.1002/anie.201307740. IF: 13.734


  • High sensitive gold-nanoparticle based lateral flow Immunodevice for Cd2+ detection in drinking waters

    López-Marzo, A.M.; Pons, J.; Blake, D.A.; Merkoçi, A. Biosensors and Bioelectronics; 47: 190 - 198. 2013. 10.1016/j.bios.2013.02.031. IF: 5.437


  • Ion-directed assembly of gold nanorods: A strategy for mercury detection

    Placido, T.; Aragay, G.; Pons, J.; Comparelli, R.; Curri, M.L.; Merkoçi, A. ACS applied materials & interfaces; 5 (3): 1084 - 1092-1092. 2013. 10.1021/am302870b. IF: 5.008


  • Micromotor-based lab-on-chip immunoassays

    García, M.; Orozco, J.; Guix, M.; Gao, W.; Sattayasamitsathit, S.; Escarpa, A.; Merkoçi, A.; Wang, J. Nanoscale; 5 (4): 1325 - 1331-1331. 2013. 10.1039/c2nr32400h. IF: 6.233


  • Multifunctional system based on hybrid nanostructured rod formation, for sensoremoval applications of Pb2+ as a model toxic metal

    López-marzo, A.M.; Pons, J.; Merkoçi, A. Journal of Materials Chemistry A; 1 (43): 13532 - 13541-13541. 2013. 10.1039/c3ta12986a. IF: 6.108


  • Nano-assembled supramolecular films from chitosan-stabilized gold nanoparticles and cobalt(II) phthalocyanine

    Silva, A.T.B.; Coelho, A.G.; Da Lopes, L.C.S.; Martins, M.V.A.; Crespilho, F.N.; Merkoçi, A.; Da Silva, W.C. Journal of the Brazilian Chemical Society; 24 (8): 1237 - 1245-1245. 2013. 10.5935/0103-5053.20130157. IF: 1.283


  • Nanomaterials for bio-functionalized electrodes: Recent trends

    Walcarius, A.; Minteer, S.D.; Wang, J.; Lin, Y.; Merkoçi, A. Journal of Materials Chemistry B; 1 (38): 4878 - 4908-4908. 2013. 10.1039/c3tb20881h. IF: 6.108


  • Nanoparticles Based Electroanalysis in Diagnostics Applications

    Merkoçi, A. Electroanalysis; 25 (1): 15 - 27-27. 2013. 10.1002/elan.201200476. IF: 2.817


  • Nanostructured CaCO3-poly(ethyleneimine) microparticles for phenol sensing in fluidic microsystem

    Mayorga-Martinez, C.C.; Hlavata, L.; Miserere, S.; López-Marzo, A.; Labuda, J.; Pons, J.; Merkoçi, A. Electrophoresis; 34 (14): 2011 - 2016-2016. 2013. 10.1002/elps.201300056. IF: 3.261


  • Paper-based electrodes for nanoparticles detection

    Parolo, C.; Medina-Sánchez, M.; Montõn, H.; De La Escosura-Muñiz, A.; Merkoçi, A. Particle and Particle Systems Characterization; 30: 662 - 666. 2013. 10.1002/ppsc.201200124. IF: 0.000


  • Paper-based nanobiosensors for diagnostics

    Parolo, C.; Merkoçi, A. Chemical Society Reviews; 42: 450 - 457. 2013. 10.1039/c2cs35255a. IF: 24.892


  • Screen-printed electrodes incorporated in a flow system for the decentralized monitoring of lead, cadmium and copper in natural and wastewater samples

    Güell, R.; Fontàs, C.; Aragay, G.; Merkoçi, A.; Anticó, E. International Journal of Environmental Analytical Chemistry; 93: 872 - 883. 2013. 10.1080/03067319.2012.684049. IF: 1.240


  • Simple paper architecture modifications lead to enhanced sensitivity in nanoparticle based lateral flow immunoassays

    Parolo, C.; Medina-Sánchez, M.; De La Escosura-Muñiz, A.; Merkoçi, A. Lab on a Chip - Miniaturisation for Chemistry and Biology; 13 (3): 386 - 390-390. 2013. 10.1039/c2lc41144j. IF: 5.697


2012

  • Analytical miniaturization and nanotechnologies

    Merkoci, A.; Kutter, J.P. Lab on a Chip - Miniaturisation for Chemistry and Biology; 12: 1915 - 1916. 2012. .


  • Bacterial Isolation by Lectin-Modified Microengines

    Campuzano, S.; Orozco, J. ; Kagan, D.; Guix, M.; Gao, W. ; Sattayasamitsathit, S. ; Claussen, J. C.; Merkoçi, A. ; Wang, J. Nano Letters; 12: 396 - 401. 2012. .


  • Bimetallic Nanowires as Electrocatalyst for Nonenzymatic Real Time Impedancimetric Detection of Glucose

    Mayorga-Martinez, C.C.; Guix, M.; Madrid, R.E; Merkoçi, A. Chemical Communications; 48: 1686 - 1688. 2012. .


  • Cancer detection using nanoparticle-based sensors

    Turner, A.; Merkoçi, A. ; Perfezou, M. Chemical Society Reviews; 41: 2606 - 2622. 2012. .


  • Carbon nanotubes and graphene in analytical sciences

    Pérez-López, B.; Merkoçi, A. Mikrochimica Acta; 179: 1 - 16. 2012. 10.1007/s00604-012-0871-9.


  • Controlled formation of nanostructured CaCO3¿PEI microparticles with high biofunctionalizing capacity

    López-Marzo, A.; Pons, J.; Merkoçi, A. Journal of Materials Chemistry; 22: 15326 - 15335. 2012. .


  • Graphene Oxide as an Optical Biosensing Platform

    Morales-Narváez, E.; Merkoçi, A. Advanced Materials; 24: 3298 - 3308. 2012. .


  • Medium Dependent Dual Turn-On/Turn-Off Fluorescence System for Heavy Metal Ions Sensing

    Aragay, G.; Alarcón, G.; Pons, J.; Font-Bardía, M.; Merkoçi, A. Journal of Physical Chemistry C; 116 (2): 1987 - 1994. 2012. 10.1021/jp210687v.


  • Nanochannels preparation and application in biosensing

    De La Escosura-Muñiz, A.; Merkoçi, A. ACS Nano; 6: 7556 - 7583. 2012. 10.1021/nn301368z.


  • Nanomaterials and lab-on-a-chip technologies

    Medina-Sánchez, M.; Miserere, S.; Merkoçi, A. Lab on a Chip - Miniaturisation for Chemistry and Biology; 12: 1932 - 1943. 2012. .


  • Nanomaterials application in electrochemical detection of heavy metals

    Aragay, G.; Merkoçi, A. Electrochimica Acta; 84: 49 - 61. 2012. .


  • Nanomaterials Based Electrochemical Sensing Applications for Safety and Security

    Marín, S.; Merkoçi, A. Electroanalysis; 24: 459 - 469. 2012. .


  • Nanomaterials for Sensing and Destroying Pesticides

    Aragay, G.; Pino, F.; Merkoçi, A. Chemical Reviews; 112: 5317 - 5338. 2012. .


  • Nanoparticles for Proteins and Cells Detection. Novel Tools for Clinical Diagnostics.

    Merkoçi, A. GIT Laboratory Journal Europe; 2012. .


  • On-chip electrochemical detection of CdS quantum dots using normal and multiple recycling flow through modes

    Medina-Sánchez, M.; Miserere, S.; Marín, S.; Aragay, G.; Merkoçi, A. Lab on a Chip - Miniaturisation for Chemistry and Biology; 12: 2000 - 2005. 2012. .


  • Signal enhancement in antibody microarrays using quantum dots nanocrystals: Application to potential Alzheimer¿s disease biomarker screening

    Morales-Narváez, E.; Montón, H.; Fomicheva, A.; Merkoçi, A. Analytical Chemistry; 84(15): 6821 - 6827. 2012. .


  • Simple Forster resonance energy transfer evidence for the ultrahigh quantum dot quenching efficiency by graphene oxide compared to other carbon structures

    Morales-Narváez, E.; Pérez-López, B.; Baptista Pires, L.; Merkoçi, A. Carbon; 50(8): 2987 - 2993. 2012. .


  • Simple monitoring of cancer cells using nanoparticles

    Maltez-Da Costa, M.; De La Escosura-Muñiz, A.; Nogués, C.; Barrios, L.; Ibáñez, E.; Merkoçi, A. Nano Letters; 12: 4164 - 4171. 2012. 10.1021/nl301726g.


  • Superhydrophobic Alkanethiol-Coated Microsubmarines for Effective Removal of Oil

    Guix, M.; Orozco, J.; García, M.; Gao, W.; Sattayasamitsathit, S.; Merkoçi, A.; Escarpa, A.; Wang, J. ACS Nano; 6(5): 4445 - 4451. 2012. DOI: 10.1021/nn301175b.


  • The use of quantum dots for immunochemistry applications

    Montón, H.; Roldán, M.; Merkoçi, A.; Rossinyol, E.; Castell, O.; Nogués, C. Methods in molecular biology (Clifton, N,J,); 906: 185 - 192. 2012. .


2011

  • Electrochemical investigation of cellular uptake of quantum dots decorated with a proline-rich cell penetrating peptide

    Marín, S.; Pujals, S.; Giralt, E.; Merkoçi, A. Bioconjugate Chemistry; 22: 180 - 185. 2011. 10.1021/bc100207w.


  • Enhanced electrochemical detection of heavy metals at heated graphite nanoparticle -based screen-printed electrodes

    Aragay, G.; Pons, J.; Merkoçi, A. Chemistry of Materials; 2011. .


  • Magnetic and electrokinetic manipulations on a microchip device for bead-based immunosensing applications

    Ambrosi, A.; Guix, M.; Merkoçi, A. Electrophoresis; 32: 861 - 869. 2011. 10.1002/elps.201000268.


  • Nanomaterials based biosensors for food analysis applications

    Pérez-López, B.; Merkoçi, A. Trends in Food Science and Technology; 22: 625 - 639. 2011. 10.1016/j.tifs.2011.04.001.


  • Nanoparticles for the development of improved (bio)sensing systems

    Pérez-López, B.; Merkoçi, A. Analytical and Bioanalytical Chemistry; 399: 1577 - 1590. 2011. 10.1007/s00216-010-4566-y.


  • Recent trends in macro-, micro-, and nanomaterial-based tools and strategies for heavy-metal detection

    Aragay, G.; Pons, J.; Merkoçi, A. Chemical Reviews; 111: 3433 - 3458. 2011. 10.1021/cr100383r.


2010

  • A Nanochannel/Nanoparticle-Based Filtering and Sensing Platform for Direct Detection of a Cancer Biomarker in Blood

    de la Escosura-Muñiz, A.; Merkoçi, A. Small; 2010. .


  • Aminopyrazole-Based Ligand Induces Gold Nanoparticle Formation and Remains Available for Heavy Metal Ions Sensing. A Simple ¿Mix and Detect¿ Approach

    Aragay, G.; Pons, J.; Ros, J.; Merkoçi, A. Langmuir : the ACS journal of surfaces and colloids; 2010. .


  • Aptamers based electrochemical biosensor for protein detection using carbon nanotubes platforms

    Kara, P.; de la Escosura-Muñiz, A.; Maltez-da Costa, M.; Guix, M.; Ozsoz, M.; Merkoçi, A. Biosensors and Bioelectronics; 26: 1715 - 1718. 2010. 10.1016/j.bios.2010.07.090.


  • Bismuth Film Combined with Screen-Printed Electrode as Biosensing Platform for Phenol Detection

    Merkoçi, A.; Anik, U.; Çevik, S.; Çubukçu, M.; Guix, M. Electroanalysis; 2010. .


  • Compact microcubic structures platform based on self-assembly Prussian blue nanoparticles with highly tuneable conductivity

    Cantanhêde Silva, W.; Guix, M.; Alarcón Angeles, G.; Merkoçi, A. Physical Chemistry Chemical Physics; 2010. .


  • Electrochemical detection of proteins using nanoparticles: applications to diagnostics

    de la Escosura-Muñiz, A.; Merkoçi, A. Expert Opinion on Medical Diagnostics; 2010. .


  • Electrochemical quantification of gold nanoparticles based on their catalytic properties toward hydrogen formation: Application in magnetoimmunoassays

    Costa, M.M.-D.; La Escosura-Muñiz, A.D.; Merkoçi, A. Electrochemistry Communications; 12: 1501 - 1504. 2010. 10.1016/j.elecom.2010.08.018.


  • Enhanced gold nanoparticle based ELISA for a breast cancer biomarker

    Ambrosi, A.; Airò, F.; Merkoçi, A. Analytical Chemistry; 82: 1151 - 1156. 2010. 10.1021/ac902492c.


  • Enzyme entrapment by ß-cyclodextrin electropolymerization onto a carbon nanotubes-modified screen-printed electrode

    Alarcón Ángeles, G. ; Guix, M. ; Silva, W.C.; Ramírez-Silva, M.T.; Palomar-Pardavé, M.; Romero-Romo, M.; Merkoçi, A. Biosensors and Bioelectronics; 2010. .


  • Gold nanoparticle-based electrochemical magnetoimmunosensor for rapid detection of anti-hepatitis B virus antibodies in human serum

    de la Escosura-Muñiz, A.; Maltez-da Costa, M.; Sánchez-Espinel, C.; Díaz-Freitas, B.; Fernández-Suarez, J.; González-Fernández, Á.; Merkoçi, A. Biosensors and Bioelectronics; 26: 1710 - 1714. 2010. 10.1016/j.bios.2010.07.069.


  • Immunosensing using nanoparticles

    De La Escosura-Muñiz, A.; Parolo, C.; Merkoçi, A. Materials Today; 13: 24 - 34. 2010. 10.1016/S1369-7021(10)70125-5.


  • Label-free voltammetric immunosensor using a nanoporous membrane based platform

    De La Escosura-Muñiz, A.; Merkoçi, A. Electrochemistry Communications; 12: 859 - 863. 2010. 10.1016/j.elecom.2010.04.007.


  • Magnetic Nanoparticles Modified with Carbon Nanotubes for Electrocatalytic Magnetoswitchable Biosensing Applications

    Pérez-López, B.; Merkoçi, A. Advanced Functional Materials; 2010. 10.1002/adfm.201001306.


  • Nanoparticle based enhancement of electrochemical DNA hybridization signal using nanoporous electrodes

    De La Escosura-Muñiz, A.; Merkoçi, A. Chemical Communications; 46: 9007 - 9009. 2010. 10.1039/c0cc02683b.


  • Nanoparticles-based strategies for DNA, protein and cell sensors

    Merkoçi, A. Biosensors and Bioelectronics; 26: 1164 - 1177. 2010. 10.1016/j.bios.2010.07.028.


  • Stable and sensitive flow-through monitoring of phenol using a carbon nanotube based screen printed biosensor

    Alarcón, G.; Guix, M.; Ambrosi, A.; Ramirez Silva, M.T. ; Palomar Pardave, M.E.; Merkoçi, A. Nanotechnology; 2010. .


  • Structural characterization by confocal laser scanning microscopy and electrochemical study of multi-walled carbon nanotube tyrosinase matrix for phenol detection

    Guix, M.; Pérez-López, B.; Sahin, M.; Roldán, M.; Ambrosi, A.; Merkoçi, A. The Analyst; 2010. .


  • Use of Sequential Injection Analysis to construct a potentiometric electronic tongue: Application to the multidetermination of heavy metals

    Mimendia, A.; Legin, A.; Merkoçi, A.; del Valle, M. Sensors and Actuators, B: Chemical; 146: 420 - 426. 2010. 10.1016/j.snb.2009.11.027.


2009

  • Controlling the electrochemical deposition of silver onto gold nanoparticles: reducing interferences and increasing the sensitivity of magnetoimmuno assays

    de la Escosura, A. ; Máltez, M.; Merkoçi, A. Biosensors and Bioelectronics; 24: 2475 - 2482. 2009. .


  • Direct electrochemical stripping detection of cystic fibrosis related DNA linked through cadmium sulphide quantum dots

    Marín, S. ; Merkoçi, A. Nanotechnology; 2009. .


  • Electrochemical analysis with nanoparticle based biosystems

    de la Escosura-Muñiz, A.; Ambrosi, A.; Merkoçi, A. TrAC - Trends in Analytical Chemistry; 27 (7): 568 - 584. 2009. 10.1016/j.trac.2008.05.008.


  • ICP-MS- a powerful technique for quantitative determination of gold nanoparticles without previous dissolving

    R. Allabashi; W. Stach; A. de la Escosura; L. Liste; A. Merkoçi Journal of Nanoparticle Research; 11: 2003 - 2011. 2009. 10.1007/s11051-008-9561-2.


  • Improvement of the electrochemical detection of catechol by the use of a carbon nanotube based biosensor

    B. Pérez; A. Merkoçi The Analyst; 134: 60 - 64. 2009. 10.1039/b808387h.


  • Lab-on-a-chip for ultrasensitive detection of carbofuran by enzymatic inhibition with replacement of enzyme using magnetic beads

    X. Llopis; M. Pumera; S. Alegret; A. Merkoçi Lab on a Chip - Miniaturisation for Chemistry and Biology; 9: 213 - 218. 2009. 10.1039/B816643A.


  • Permeability improvement of electropolymerized polypyrrole films in water using magnetic hydrophilic microbeads

    S. Cosnier; S. N. Ding; A. Pellissier; K. Gorgy; M. Holzinger; B. Pérez López; A. Merkoçi Electroanalysis; 21 (7): 887 - 890. 2009. 10.1002/elan.200804484 .


  • Rapid identification and quantification of tumor cells using an electrocatalytic method based on gold nanoparticles

    De La Escosura-Muñiz, A.; Sánchez-Espinel, C.; Díaz-Freitas, B.; González-Fernández, Á.; Maltez-Da Costa, M.; Merkoçi, A. Analytical Chemistry; 81: 10268 - 10274. 2009. 10.1021/ac902087k.


2008

  • A Carbon Nanotube PVC Based Matrix Modified with Glutaraldehyde Suitable for Biosensor Applications

    Briza Pérez; Joan Sola; Salvador Alegret; Arben Merkoçi Electroanalysis; 6: 603 - 610. 2008. 10.1002/elan.200704119.


  • Enhanced host guest electrochemical recognition of dopamine using cyclodextrin in the presence of carbon nanotubes

    G. Alarcon Angeles; B. Pérez López; M. Palomar-Pardave; M. T. Ramírez-Silva; S. Alegret; A. Merkoçi Carbon; 46 (6): 898 - 906. 2008. 10.1016/j.carbon.2008.02.025.


  • Sensitive and stable monitoring of lead and cadmium in seawater using screen-printed electrode and electrochemical stripping analysis

    Raquel Güell; Gemma Aragay; Clàudia Fontàs; Enriqueta Anticó; Arben Merkoçi Analytical Chemistry; 627: 219 - 224. 2008. 10.1016/j.aca.2008.08.017.


  • Silver, gold and the corresponding core shell nanoparticles: synthesis and characteritzation

    Fraser Douglas; Ramon Yanez; Josep Ros; Sergio Marín; Alfredo de la Escosura; Salvador Alegret; Arben Merkoçi Journal of Nanoparticle Research; 10: 97 - 106. 2008. 10.1007/s11051-008-9374-3.


  • The Usage of Bismuth Film Electrode as Transducer in Glucose Biosensing

    Ülkü An¿k (K¿rgöz); Suna Timur; Meliha Çubukçu; Arben Merkoçi Mikrochimica Acta; 160: 269 - 273. 2008. 10.1007/s00604-007-0868-y.


2007

  • Carbon nanofiber vs. carbon microparticles as modifiers of glassy carbon and gold electrodes applied in electrochemical sensing of NADH

    Briza Pérez; Manel del Valle; Salvador Alegret; Arben Merkoçi Talanta; 74: 398 - 404. 2007. .


  • Carbon nanotube composite as novel platform for microbial biosensor

    Ülkü A. Kirgoz; Suna Timur; Dilek Odaci; Briza Pérez; Salvador Alegret; Arben Merkoçi Electroanalysis; 19: 893 - 898. 2007. 10.1002/elan.200603786.


  • Carbon nanotube detectors for microchip CE: Comparative study of single-wall and multiwall carbon nanotube, and graphite powder films on glassy carbon, gold, and platinum electrode surfaces

    Martin Pumera; Arben Merkoçi; Salvador Alegret Electrophoresis; 28: 1274 - 1280. 2007. 10.1002/elps.200600632.


  • Detection of cadmium sulphide nanoparticles by using screen-printed electrodes and a handheld device

    Arben Merkoçi; Luiz Humberto Marcolino-Junior; Sergio Marín; Orlando Fatibello-Filho; Salvador Alegret. Nanotechnology; 18: 35502. 2007. 10.1088/0957-4484/18/3/035502.


  • Double-Codified Gold Nanolabels for Enhanced Immunoanalysis

    Adriano Ambrosi; Maria Teresa Castañeda; Anthony J. Killard; Malcolm R. Smyth; Salvador Alegret; Arben Merkoçi Analytical Chemistry; 79 (14): 5232 - 5240. 2007. 10.1021/ac070357m.


  • Electrochemical biosensing with nanoparticles (Invited review for the Minireview Series Nanobiotechnology by Itamar Willner)

    Arben Merkoçi FEBS Journal; 274: 310 - 316. 2007. 10.1111/j.1742-4658.2006.05603.x.


  • Electrochemical genosensors for biomedical applications based on gold nanoparticles

    M.T. Castañeda; A. Merkoçi; M. Pumera; S. Alegret Biosensors and Bioelectronics; 22: 1961 - 1967. 2007. 10.1016/j.bios.2006.08.031,.


  • Electrochemical sensing of DNA using gold nanoparticles

    M.T.Castañeda; S.Alegret; A.Merkoçi Electroanalysis; 19: 743 - 753. 2007. 10.1002/elan.200603784.


  • Nanobiomaterials in Electroanalysis

    A. Merkoçi Electroanalysis; 2007. .