Staff directory Neus Gómez Bastus

Neus Gómez Bastus

Senior Researcher
Inorganic Nanoparticles



  • Addressing Nanomaterial Immunosafety by Evaluating Innate Immunity across Living Species

    Boraschi D., Alijagic A., Auguste M., Barbero F., Ferrari E., Hernadi S., Mayall C., Michelini S., Navarro Pacheco N.I., Prinelli A., Swart E., Swartzwelter B.J., Bastús N.G., Canesi L., Drobne D., Duschl A., Ewart M.-A., Horejs-Hoeck J., Italiani P., Kemmerling B., Kille P., Prochazkova P., Puntes V.F., Spurgeon D.J., Svendsen C., Wilde C.J., Pinsino A. Small; 16 (21, 2000598) 2020. 10.1002/smll.202000598. IF: 10.856

    The interaction of a living organism with external foreign agents is a central issue for its survival and adaptation to the environment. Nanosafety should be considered within this perspective, and it should be examined that how different organisms interact with engineered nanomaterials (NM) by either mounting a defensive response or by physiologically adapting to them. Herein, the interaction of NM with one of the major biological systems deputed to recognition of and response to foreign challenges, i.e., the immune system, is specifically addressed. The main focus is innate immunity, the only type of immunity in plants, invertebrates, and lower vertebrates, and that coexists with adaptive immunity in higher vertebrates. Because of their presence in the majority of eukaryotic living organisms, innate immune responses can be viewed in a comparative context. In the majority of cases, the interaction of NM with living organisms results in innate immune reactions that eliminate the possible danger with mechanisms that do not lead to damage. While in some cases such interaction may lead to pathological consequences, in some other cases beneficial effects can be identified. © 2020 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

  • Hepato(Geno)toxicity assessment of nanoparticles in a hepg2 liver spheroid model

    Elje E., Mariussen E., Moriones O.H., Bastús N.G., Puntes V., Kohl Y., Dusinska M., Rundén-Pran E. Nanomaterials; 10 (3, 545) 2020. 10.3390/nano10030545. IF: 4.034

    (1) In compliance with the 3Rs policy to reduce, refine and replace animal experiments, the development of advanced in vitro models is needed for nanotoxicity assessment. Cells cultivated in 3D resemble organ structures better than 2D cultures. This study aims to compare cytotoxic and genotoxic responses induced by titanium dioxide (TiO2), silver (Ag) and zinc oxide (ZnO) nanoparticles (NPs) in 2D monolayer and 3D spheroid cultures of HepG2 human liver cells. (2) NPs were characterized by electron microscopy, dynamic light scattering, laser Doppler anemometry, UV-vis spectroscopy and mass spectrometry. Cytotoxicity was investigated by the alamarBlue assay and confocal microscopy in HepG2 monolayer and spheroid cultures after 24 h of NP exposure. DNA damage (strand breaks and oxidized base lesions) was measured by the comet assay. (3) Ag-NPs were aggregated at 24 h, and a substantial part of the ZnO-NPs was dissolved in culture medium. Ag-NPs induced stronger cytotoxicity in 2D cultures (EC50 3.8 µg/cm2) than in 3D cultures (EC50 > 30 µg/cm2), and ZnO-NPs induced cytotoxicity to a similar extent in both models (EC50 10.1–16.2 µg/cm2). Ag-and ZnO-NPs showed a concentration-dependent genotoxic effect, but the effect was not statistically significant. TiO2-NPs showed no toxicity (EC50 > 75 µg/cm2). (4) This study shows that the HepG2 spheroid model is a promising advanced in vitro model for toxicity assessment of NPs. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.

  • Increasing complexity of nanocrystals

    Bastús N.G., Gonzalez E., Puntes V. Nano Today; 32 (100859) 2020. 10.1016/j.nantod.2020.100859. IF: 16.582

    [No abstract available]

  • MOF-Beads Containing Inorganic Nanoparticles for the Simultaneous Removal of Multiple Heavy Metals from Water

    Boix G., Troyano J., Garzón-Tovar L., Camur C., Bermejo N., Yazdi A., Piella J., Bastus N.G., Puntes V.F., Imaz I., Maspoch D. ACS Applied Materials and Interfaces; 12 (9): 10554 - 10562. 2020. 10.1021/acsami.9b23206. IF: 8.456

    Pollution of water with heavy metals is a global environmental problem whose impact is especially severe in developing countries. Among water-purification methods, adsorption of heavy metals has proven to be simple, versatile, and cost-effective. However, there is still a need to develop adsorbents with a capacity to remove multiple metal pollutants from the same water sample. Herein, we report the complementary adsorption capacities of metal-organic frameworks (here, UiO-66 and UiO-66-(SH)2) and inorganic nanoparticles (iNPs; here, cerium-oxide NPs) into composite materials. These adsorbents, which are spherical microbeads generated in one step by continuous-flow spray-drying, efficiently and simultaneously remove multiple heavy metals from water, including As(III and V), Cd(II), Cr(III and VI), Cu(II), Pb(II), and Hg(II). We further show that these microbeads can be used as a packing material in a prototype of a continuous-flow water treatment system, in which they retain their metal-removal capacities upon regeneration with a gentle acidic treatment. As proof-of-concept, we evaluated these adsorbents for purification of laboratory water samples prepared to independently recapitulate each of two strongly polluted rivers: the Bone (Indonesia) and Buringanga (Bangladesh) rivers. In both cases, our microbeads reduced the levels of all the metal contaminants to below the corresponding permissible limits established by the World Health Organization (WHO). Moreover, we demonstrated the capacity of these microbeads to lower levels of Cr(VI) in a water sample collected from the Sarno River (Italy). Finally, to create adsorbents that could be magnetically recovered following their use in water purification, we extended our spray-drying technique to simultaneously incorporate two types of iNPs (CeO2 and Fe3O4) into UiO-66-(SH)2, obtaining CeO2/Fe3O4@UiO-66-(SH)2 microbeads that adsorb heavy metals and are magnetically responsive. Copyright © 2020 American Chemical Society.

  • Understanding galvanic replacement reactions: the case of Pt and Ag

    Merkoçi F., Patarroyo J., Russo L., Piella J., Genç A., Arbiol J., Bastús N.G., Puntes V. Materials Today Advances; 5 (100037) 2020. 10.1016/j.mtadv.2019.100037. IF: 0.000

    Synthesis of nanocrystals (NCs), where material science elements are addressed with organic chemistry precision techniques, is especially challenging and difficult to control. This difficulty arises from the increased complexity of the mineralization processes and the generation of a liquid-solid interface. These aspects, along with a strong susceptibility to reaction kinetics, ultimately translate into serious challenges for reproducibility and morphological control. By systematically varying the different parameters used to control the morphology of NCs, including complexing agents, coreducers, and cooxidants, the general reaction landscape can be mapped and the most stable and reproducible recipes can be identified. We apply this concept to the model transmetallation reaction between immiscible Pt and Ag forming hollow Pt NCs by galvanic replacement reactions. In this work, 648 synthetic recipes were performed and characterized per duplicate, from which a subset of 307 recipes leading to the controlled formation of hollow NCs were further analyzed to correlate reaction conditions with the final obtained structure and stability (reproducibility). As a result, we present robust general synthetic protocols leading to the ad hoc production of Pt-based hollow NCs with independent control of shell thickness, void size, surface roughness, and degree of porosity. © 2019 The Authors


  • Assessment of iron oxide nanoparticle ecotoxicity on regeneration and homeostasis in the replacement model system Schmidtea mediterranea

    Tran T.A., Hesler M., Moriones O.H., Jimeno-Romero A., Fischer B., Bastús N.G., Puntes V., Wagner S., Kohl Y.L., Gentile L. ALTEX; 36 (4): 583 - 596. 2019. 10.14573/altex.1902061. IF: 6.183

    Iron oxide nanoparticles (IONs) are used in a number of applications, from food to cosmetics, from medical applications to magnetic storage. In spite of the 550 tons produced each year in Europe alone, no effective dose limit recommendations are established and the overall risks connected to IONs are still debated. The incorporation of IONs in daily life raises a concern about their effects on the environment, on living organisms, and on human health. In this study, we used freshwater planarians to assess the nanoecotoxicity of IONs. Planarians are free-living invertebrates known for their astonishing regenerative ability. Because of their sensitivity to toxicants, they are often used to determine the effects of toxic, genotoxic and carcinogenic environmental compounds with an approach in line with the 3Rs (Reduce, Refine, Replace) principle. Planarians were exposed to IONs at concentrations up to 1 mg/mL and their effects were evaluated at the behavioral, morphofunctional and molecular levels, with a special emphasis on the regeneration process. Our results indicate that IONs did not affect the stem cell population dynamics, nor did they induce substantial changes in either homeostatic or regenerating planarians. As positive controls, gold nanoparticles coated with the pro-apoptotic anti-cancer drug hexadecylmethylammonium bromide, silver nanoparticles and highly concentrated polystyrene nanoparticles were used. These all elicited toxic effects. Therefore, we conclude that IONs at environmental concentrations are safe for planarians, and that the planarian is a powerful model system that can replace vertebrate animal models in nanoecotoxicology research and for nanoecotoxicology studies.

  • Dynamic Equilibrium in the Cetyltrimethylammonium Bromide-Au Nanoparticle Bilayer, and the Consequent Impact on the Formation of the Nanoparticle Protein Corona

    Barbero F., Moriones O.H., Bastús N.G., Puntes V. Bioconjugate Chemistry; 2019. 10.1021/acs.bioconjchem.9b00624. IF: 4.349

    Nanoparticles in ionic solutions are usually surrounded by stabilizing molecules that avoid aggregation and determine their surface properties, which strongly influence their behavior. The present work aims to shed light on the static vs dynamic nature of the cetyltrimethylammonium bromide (CTAB) bilayer on gold nanoparticles and to understand its effects on nanoparticle evolution in biological systems. A systematic study of the CTAB bilayer of Au nanorods and nanospheres was carried out, exploring the role of excess free surfactant in solution on the surface properties of nanoparticles and their colloidal stability. The results indicated the presence of a CTAB bilayer in which the external layer was in rapid dynamic equilibrium with the free surfactant in solution. The internal surfactant layer of the gold nanospheres was also found to be in dynamic equilibrium. Conversely, the gold nanorods had a permanent internal layer. Consequently, the CTAB-nanoparticle dispersions always contained free CTAB in excess to maintain the colloidal stability of the NPs. In contrast, decreasing the free CTAB concentration resulted in nanoparticle aggregation. The impact of the dynamic equilibrium on the exposure of particles to biological fluids and on the formation of the nanoparticle protein corona was studied, revealing the different fates of the nanoparticles, which depended on the amount of free CTAB in solution. © 2019 American Chemical Society.

  • Hollow PdAg-CeO2 heterodimer nanocrystals as highly structured heterogeneous catalysts

    Patarroyo J., Delgado J.A., Merkoçi F., Genç A., Sauthier G., Llorca J., Arbiol J., Bastus N.G., Godard C., Claver C., Puntes V. Scientific Reports; 9 (1, 18776) 2019. 10.1038/s41598-019-55105-x. IF: 4.011

    In the present work, hollow PdAg-CeO2 heterodimer nanocrystals (NCs) were prepared and tested as catalysts for the selective hydrogenation of alkynes. These nanostructures combine for the first time the beneficial effect of alloying Pd with Ag in a single NC hollow domain with the formation of active sites at the interface with the CeO2 counterpart in an additive manner. The PdAg-CeO2 NCs display excellent alkene selectivity for aliphatic alkynes. For the specific case of hydrogenation of internal alkynes such as 4-octyne, very low over-hydrogenation and isomerization products were observed over a full conversion regime, even after prolonged reaction times. These catalytic properties were remarkably superior in comparison to standard catalysts. The promotion of Ag on the moderation of the reactivity of the Pd phase, in combination with the creation of interfacial sites with the CeO2 moiety in the same nanostructure, is pointed as the responsible of such a remarkable catalytic performance. © 2019, The Author(s).

  • Mechanomodulation of Lipid Membranes by Weakly Aggregating Silver Nanoparticles

    Arribas Perez M., Moriones O.H., Bastús N.G., Puntes V., Nelson A., Beales P.A. Biochemistry; 58 (47): 4761 - 4773. 2019. 10.1021/acs.biochem.9b00390. IF: 2.952

    Silver nanoparticles (AgNPs) have wide-ranging applications, including as additives in consumer products and in medical diagnostics and therapy. Therefore, understanding how AgNPs interact with biological systems is important for ascertaining any potential health risks due to the likelihood of high levels of human exposure. Besides any severe, acute effects, it is desirable to understand more subtle interactions that could lead to milder, chronic health impacts. Nanoparticles are small enough to be able to enter biological cells and interfere with their internal biochemistry. The initial contact between the nanoparticle and cell is at the plasma membrane. To gain fundamental mechanistic insight into AgNP-membrane interactions, we investigate these phenomena in minimal model systems using a wide range of biophysical approaches applied to lipid vesicles. We find a strong dependence on the medium composition, where colloidally stable AgNPs in a glucose buffer have a negligible effect on the membrane. However, at physiological salt concentrations, the AgNPs start to weakly aggregate and sporadic but significant membrane perturbation events are observed. Under these latter conditions, transient poration and structural remodeling of some vesicle membranes are observed. We observe that the fluidity of giant vesicle membranes universally decreases by an average of 16% across all vesicles. However, we observe a small population of vesicles that display a significant change in their mechanical properties with lower bending rigidity and higher membrane tension. Therefore, we argue that the isolated occurrences of membrane perturbation by AgNPs are due to low-probability mechanomodulation by AgNP aggregation at the membrane. © 2019 American Chemical Society.

  • Seeded-Growth Aqueous Synthesis of Colloidal-Stable Citrate-Stabilized Au/CeO2 Hybrid Nanocrystals: Heterodimers, Core@Shell, and Clover- And Star-Like Structures

    Piella J., Gónzalez-Febles A., Patarroyo J., Arbiol J., Bastús N.G., Puntes V. Chemistry of Materials; 31 (19): 7922 - 7932. 2019. 10.1021/acs.chemmater.9b02005. IF: 10.159

    Well-defined colloidal-stable citrate-stabilized Au/CeO2 hybrid nanocrystals (NCs) with coherent quasi-epitaxial interfaces and unprecedented control of their architectural and morphological characteristics have been synthesized via a novel and straightforward seeded-growth aqueous approach. The synthetic strategy, based on the identification of the experimental conditions under which the heterogeneous nucleation and growth processes of CeO2 onto presynthesized Au are controlled, allows for the fine adjustment of each individual domain in the structure, particularly the size of the Au core (from 5 to 100 nm), the thickness of the CeO2 shell (from 5 to 20 nm), and the growth mode of CeO2 onto Au NCs (from core@shell to heterodimer, clover- and star-like structures). This morphological control is achieved by the rational use of sodium citrate, which plays multiple key roles, as a reducer and stabilizing agent in the preparation of Au NCs, and as a complexing agent of Ce3+ for its controlled oxidation and hydrolysis during the subsequent CeO2 deposition. The resultant Au/CeO2 NCs remain stable and well-dispersed in water, allowing us to study the impact of fine variations of the NC structure on the underlying optical response. This level of morphological control, as well as the ease by which such well-defined nanostructures are produced, opens new opportunities for systematically investigating the interactions between individual components in designing more advanced complex NCs. Remarkably, because no organic solvents are used and no toxic waste is formed during the reaction, the proposed synthesis method can be defined as sustainable, viable, and cost-effective. Copyright © 2019 American Chemical Society.


  • Fluorescently labelled nanomaterials in nanosafety research: Practical advice to avoid artefacts and trace unbound dye

    Murray R.A., Escobar A., Bastús N.G., Andreozzi P., Puntes V., Moya S.E. NanoImpact; 9: 102 - 113. 2018. 10.1016/j.impact.2017.11.001. IF: 0.000

    Fluorescence labelling has become a fundamental tool in nanotoxicological research. There are, however, certain drawbacks when dealing with the labelling of nanomaterials. Very often the leaching of dye from the nanomaterial or the presence of unbound dyes in solution leads to the incorrect quantification and localisation of nanomaterials in cells. In this review article we will discuss possible situations, which may give rise to incorrect quantification of the fluorescence associated with nanomaterials and their consequences in the evaluation of the fate of the nanomaterial and its intracellular dose. Issues related to the labelling strategies, dye photostability, impact of the dye on the properties of the nanomaterial surface, and the presence of unbound dye will be discussed. We will also show how Fluorescence Correlation Spectroscopy can be used to trace the presence of free label in solution. In addition, we will discuss the interaction of fluorescence molecules with metallic nanoparticles which can lead to an enhancement or quenching of fluorescence depending on the distance between the dye and the nanoparticle surface. Finally, we will compare the fluorescence emission originating from quantum dots and organic molecules. © 2017 Elsevier B.V.

  • Sequential Deconstruction-Reconstruction of Metal-Organic Frameworks: An Alternative Strategy for Synthesizing (Multi)-Layered ZIF Composites

    Avci C., Yazdi A., Tarrés M., Bernoud E., Bastús N.G., Puntes V., Imaz I., Ribas X., Maspoch D. ACS Applied Materials and Interfaces; 10 (28): 23952 - 23960. 2018. 10.1021/acsami.8b05098. IF: 8.097

    Here, we report the synthesis of (multi)-layered zeolitic imidazolate framework (ZIF-8/-67) composite particles via a sequential deconstruction-reconstruction process. We show that this process can be applied to construct ZIF-8-on-ZIF-67 composite particles whose cores are the initially etched particles. In addition, we demonstrate that introduction of functional inorganic nanoparticles (INPs) onto the crystal surface of etched particles does not disrupt ZIF particle reconstruction, opening new avenues for designing (multi)-layered ZIF-on-INP-on-ZIF composite particles comprising more than one class of inorganic nanoparticles. In these latter composites, the location of the inorganic nanoparticles inside each single metal-organic framework particle as well as of their separation at the nanoscale (20 nm) is controlled. Preliminary results show that (multi)-layered ZIF-on-INP-on-ZIF composite particles comprising a good sequence of inorganic nanoparticles can potentially catalyze cascade reactions. Copyright © 2018 American Chemical Society.

  • Time- and Size-Resolved Plasmonic Evolution with nm Resolution of Galvanic Replacement Reaction in AuAg Nanoshells Synthesis

    Russo L., Merkoçi F., Patarroyo J., Piella J., Merkoçi A., Bastús N.G., Puntes V. Chemistry of Materials; 30 (15): 5098 - 5107. 2018. 10.1021/acs.chemmater.8b01488. IF: 9.890

    The rational design of advanced nanomaterials with enhanced optical properties can be reached only with the profound thermodynamic and kinetic understanding of their synthetic processes. In this work, the synthesis of monodisperse AuAg nanoshells with thin shells and large voids is achieved through the development of a highly reproducible and robust methodology based on the galvanic replacement reaction. This is obtained thanks to the systematic identification of the role played by the different synthetic parameters involved in the process (such as surfactants, co-oxidizers, complexing agents, time, and temperature), providing an unprecedented control over the material's morphological and optical properties. Thus, the time- and size-resolved evolution of AuAg nanoshells surface plasmon resonance band is described for 15, 30, 60, 80, 100, and 150 nm-sized particles spanning almost through the entire visible spectrum. Its analysis reveals a four-phase mechanism coherent with the material's morphological transformation. Simulations based on Mie's theory confirm the observed optical behavior in AuAg nanoshells formation and provide insights into the influence of the Au/Ag ratio on their plasmonic properties. The high degree of morphological control provided by this methodology represents a transferable and scalable strategy for the development of advanced-generation plasmonic nanomaterials. © 2018 American Chemical Society.


  • Formation of the Protein Corona: The Interface between Nanoparticles and the Immune System

    Barbero F., Russo L., Vitali M., Piella J., Salvo I., Borrajo M.L., Busquets-Fité M., Grandori R., Bastús N.G., Casals E., Puntes V. Seminars in Immunology; 34: 52 - 60. 2017. 10.1016/j.smim.2017.10.001. IF: 9.611

    The interaction of inorganic nanoparticles and many biological fluids often withstands the formation of a Protein Corona enveloping the nanoparticle. This Protein Corona provides the biological identity to the nanoparticle that the immune system will detect. The formation of this Protein Corona depends not only on the composition of the nanoparticle, its size, shape, surface state and exposure time, but also on the type of media, nanoparticle to protein ratio and the presence of ions and other molecular species that interfere in the interaction between proteins and nanoparticles. This has important implications on immune safety, biocompatibility and the use of nanoparticles in medicine. © 2017 Elsevier Ltd

  • Hollow metal nanostructures for enhanced plasmonics: Synthesis, local plasmonic properties and applications

    Genç A., Patarroyo J., Sancho-Parramon J., Bastús N.G., Puntes V., Arbiol J. Nanophotonics; 6 (1): 193 - 213. 2017. 10.1515/nanoph-2016-0124. IF: 4.492

    Metallic nanostructures have received great attention due to their ability to generate surface plasmon resonances, which are collective oscillations of conduction electrons of a material excited by an electromagnetic wave. Plasmonic metal nanostructures are able to localize and manipulate the light at the nanoscale and, therefore, are attractive building blocks for various emerging applications. In particular, hollow nanostructures are promising plasmonic materials as cavities are known to have better plasmonic properties than their solid counterparts thanks to the plasmon hybridization mechanism. The hybridization of the plasmons results in the enhancement of the plasmon fields along with more homogeneous distribution as well as the reduction of localized surface plasmon resonance (LSPR) quenching due to absorption. In this review, we summarize the efforts on the synthesis of hollow metal nanostructures with an emphasis on the galvanic replacement reaction. In the second part of this review, we discuss the advancements on the characterization of plasmonic properties of hollow nanostructures, covering the single nanoparticle experiments, nanoscale characterization via electron energy-loss spectroscopy and modeling and simulation studies. Examples of the applications, i.e. sensing, surface enhanced Raman spectroscopy, photothermal ablation therapy of cancer, drug delivery or catalysis among others, where hollow nanostructures perform better than their solid counterparts, are also evaluated. © 2016 Aziz Genç, Jordi Arbiol et al., published by De Gruyter.

  • Modeling the Optical Responses of Noble Metal Nanoparticles Subjected to Physicochemical Transformations in Physiological Environments: Aggregation, Dissolution and Oxidation

    Piella J., Bastús N.G., Puntes V. Zeitschrift fur Physikalische Chemie; 231 (1): 33 - 50. 2017. 10.1515/zpch-2016-0874. IF: 1.012

    Herein, we study how optical properties of colloidal dispersions of noble metal nanoparticles (Au and Ag) are affected by processes such as aggregation and oxidative dissolution. The optical contributions of these processes to the extinction spectra in the UV-vis region are often overlapped, making difficult its interpretation. In this regard, modeling the UV-vis spectra (in particular absorbance curve, peaks position, intensity and full width at half maximum-FWHM) of each process separately offers a powerful tool to identify the transformation of NPs under relevant and complex scenarios, such as in biological media. The proper identification of these transformations is crucial to understand the biological effects of the NPs. © 2017 Walter de Gruyter GmbH, Berlin/Boston.

  • One-Pot Synthesis of Cationic Gold Nanoparticles by Differential Reduction

    Sperling R.A., Garciá-Fernández L., Ojea-Jiménez I., Piella J., Bastús N.G., Puntes V. Zeitschrift fur Physikalische Chemie; 231 (1): 7 - 18. 2017. 10.1515/zpch-2016-0864. IF: 1.012

    The size-controlled synthesis of cationic particles by differential reduction of HAuCl4 precursor in the presence of NaBH4 and 1-aminoundecane-12-thiol (AUT) is reported. The number of seed particles is determined by the fraction of the initially Au precursor reduced by NaBH4 present in the reaction mixture, which are then grown larger by the AUT, acting as both weak reducing agent and stabilizing surfactant. By this methodology, size controlled synthesis is achieved in a two-step one-pot synthesis at room temperature. © 2017 Walter de Gruyter GmbH, Berlin/Boston.

  • Probing the surface reactivity of nanocrystals by the catalytic degradation of organic dyes: The effect of size, surface chemistry and composition

    Piella J., Merkoçi F., Genç A., Arbiol J., Bastús N.G., Puntes V. Journal of Materials Chemistry A; 5 (23): 11917 - 11929. 2017. 10.1039/c7ta01328k. IF: 8.867

    We herein present a comprehensive study on how the catalytic performance and reusability of Au nanocrystals (NCs) are affected by systematic variations of crystal size, surface coating and composition. The reductions of different organic dyes (4-nitrophenol, rhodamine B and methylene blue) by borohydride ions were used as model catalytic reactions. The catalytic performance of the Au NCs ranged between 3.6 to 110 nm was found to be dependent on crystal size, indicating that Au surface atoms have a distinct size-dependent reactivity in this reaction. Similarly, the catalytic performance was found to be strongly dependent on the nature of the coating molecule, obtaining lower catalytic activities for molecules strongly bound to the Au surface. Finally, the catalytic performance was found to be dependent on the chemical composition of the NC (Au, Ag, Pt) and the model dye used as a testing system, with the highest degradation rate found for methylene blue, followed by 4-nitrophenol and rhodamine B. We believe that this study provides a better understanding of the catalytic performance of Au NCs upon controlled modifications of the structural and morphological parameters, and a working environment that can be used to facilitate the selection of the optimum NC size, coating molecule and evaluation system for a particular study of interest. © 2017 The Royal Society of Chemistry.

  • Seeded Growth Synthesis of Au-Fe3O4 Heterostructured Nanocrystals: Rational Design and Mechanistic Insights

    Fantechi E., Roca A.G., Sepúlveda B., Torruella P., Estradé S., Peiró F., Coy E., Jurga S., Bastús N.G., Nogués J., Puntes V. Chemistry of Materials; 29 (9): 4022 - 4035. 2017. 10.1021/acs.chemmater.7b00608. IF: 9.466

    Multifunctional hybrid nanoparticles comprising two or more entities with different functional properties are gaining ample significance in industry and research. Due to its combination of properties, a particularly appealing example is Au-Fe3O4 composite nanoparticles. Here we present an in-depth study of the synthesis of Au-Fe3O4 heterostructured nanocrystals (HNCs) by thermal decomposition of iron precursors in the presence of preformed 10 nm Au seeds. The role of diverse reaction parameters on the HNCs formation was investigated using two different precursors: iron pentacarbonyl (Fe(CO)5) and iron acetylacetonate (Fe(acac)3). The reaction conditions promoting the heterogeneous nucleation of Fe3O4 onto Au seeds were found to significantly differ depending on the precursor chosen, where Fe(acac)3 is considerably more sensitive to the variation of the parameters than Fe(CO)5 and more subject to homogeneous nucleation processes with the consequent formation of isolated iron oxide nanocrystals (NCs). The role of the surfactants was also crucial in the formation of well-defined and monodisperse HNCs by regulating the access to the Au surface. Similarly, the variations of the [Fe]/[Au] ratio, temperature, and employed solvent were found to act on the mean size and the morphology of the obtained products. Importantly, while the optical properties are rather sensitive to the final morphology, the magnetic ones are rather similar for the different types of obtained HNCs. The surface functionalization of dimer-like HNCs with silica allows their dispersion in aqueous media, opening the path to their use in biomedical applications. © 2017 American Chemical Society.

  • Size-Dependent Protein-Nanoparticle Interactions in Citrate-Stabilized Gold Nanoparticles: The Emergence of the Protein Corona

    Piella J., Bastús N.G., Puntes V. Bioconjugate chemistry; 28 (1): 88 - 97. 2017. 10.1021/acs.bioconjchem.6b00575. IF: 4.818

    Surface modifications of highly monodisperse citrate-stabilized gold nanoparticles (AuNPs) with sizes ranging from 3.5 to 150 nm after their exposure to cell culture media supplemented with fetal bovine serum were studied and characterized by the combined use of UV-vis spectroscopy, dynamic light scattering, and zeta potential measurements. In all the tested AuNPs, a dynamic process of protein adsorption was observed, evolving toward the formation of an irreversible hard protein coating known as Protein Corona. Interestingly, the thickness and density of this protein coating were strongly dependent on the particle size, making it possible to identify different transition regimes as the size of the particles increased: (i) NP-protein complexes (or incomplete corona), (ii) the formation of a near-single dense protein corona layer, and (iii) the formation of a multilayer corona. In addition, the different temporal patterns in the evolution of the protein coating came about more quickly for small particles than for the larger ones, further revealing the significant role that size plays in the kinetics of this process. Since the biological identity of the NPs is ultimately determined by the protein corona and different NP-biological interactions take place at different time scales, these results are relevant to biological and toxicological studies.


  • One-pot polyol synthesis of highly monodisperse short green silver nanorods

    Patarroyo J., Genç A., Arbiol J., Bastús N.G., Puntes V. Chemical Communications; 52 (73): 10960 - 10963. 2016. 10.1039/c6cc04796c. IF: 6.567

    Green silver nanorods (Ag NRs) of a low aspect ratio (2.8) have been produced in high yields via an optimized, simple, and robust one-pot polyol method in the presence of tannic acid, which favors the nucleation of decahedral seeds needed for the production of monodisperse Ag NRs. These Ag NRs were further used as sacrificial templates to produce Au hollow nanostructures via galvanic replacement reaction with HAuCl4 at room temperature. © 2016 The Royal Society of Chemistry.

  • Quantifying the Sensitivity of Multipolar (Dipolar, Quadrupolar, and Octapolar) Surface Plasmon Resonances in Silver Nanoparticles: The Effect of Size, Composition, and Surface Coating

    Bastús N.G., Piella J., Puntes V. Langmuir; 32 (1): 290 - 300. 2016. 10.1021/acs.langmuir.5b03859. IF: 3.993

    The effect of composition, size, and surface coating on the sensitivity of localized multipolar surface plasmon resonances has been spectroscopically investigated in high-quality silver colloidal solutions with precisely controlled sizes from 10 to 220 nm and well-defined surface chemistry. Surface plasmon resonance modes have been intensively characterized, identifying the size-dependence of dipolar, quadrupolar, and octapolar modes. Modifications of the NP's surface chemistry revealed the higher sensitivity of large sizes, long molecules, thiol groups, and low-order resonance modes. We also extend this study to gold nanoparticles, aiming to compare the sensitivity of both materials, quantifying the higher sensitivity of silver. © 2015 American Chemical Society.

  • Shell or Dots - Precursor Controlled Morphology of Au-Se Deposits on CdSe Nanoparticles

    De La Cueva L., Meyns M., Bastús N.G., Rodríguez-Fernández J., Otero R., Gallego J.M., Alonso C., Klinke C., Juárez B.H. Chemistry of Materials; 28 (8): 2704 - 2714. 2016. 10.1021/acs.chemmater.6b00287. IF: 9.407

    The most prevalent image of the morphology of Au-CdSe hybrid nanoparticles (HNPs) is that of dumbbells or matchsticks with CdSe nanoparticles (NPs) acting as seed material onto which spherical Au dots are deposited. On the basis of a system with only three reaction components, CdSe seeds, n-dodecyltrimethylammonium bromide-complexed AuCl3, and dodecanethiol, we demonstrate how the morphology of the Au deposits on the semiconductor NPs, either in the form of dots on the vertices or in the form of a shell around the NP surface, can be determined by controlling the oxidation state of the metal precursor. Furthermore, we apply X-ray photoelectron spectroscopy to show that the resultant deposits are composed of partially oxidized Au, corresponding to a Au-Se compound regardless the deposit morphology. To obtain a detailed characterization of the HNPs with different morphologies and to gain mechanistic insights into the deposition process, (cryogenic) high-resolution transmission electron microscopy, mass spectrometry, cyclic voltammetry, and computational simulations have been performed. Our results emphasize that the knowledge of the surface chemistry of the seed particles as well as a defined picture of the metal precursors is necessary to understand heterodeposition processes. © 2016 American Chemical Society.

  • Size-Controlled Synthesis of Sub-10-nanometer Citrate-Stabilized Gold Nanoparticles and Related Optical Properties.

    Piella J., Bastús N.G., Puntes V. Chemistry of Materials; 28 (4): 1066 - 1075. 2016. 10.1021/acs.chemmater.5b04406. IF: 9.407

    Highly monodisperse, biocompatible and functionalizable sub-10-nm citrate-stabilized gold nanoparticles (Au NPs) have been synthesized following a kinetically controlled seeded-growth strategy. The use of traces of tannic acid together with an excess of sodium citrate during nucleation is fundamental in the formation of a high number (7 × 1013 NPs/mL) of small ∼3.5 nm Au seeds with a very narrow distribution. A homogeneous nanometric growth of these seeds is then achieved by adjusting the reaction parameters: pH, temperature, sodium citrate concentration and gold precursor to seed ratio. We use this method to produce Au NPs with a precise control over their sizes between 3.5 and 10 nm and a versatile surface chemistry allowing studying the size-dependent optical properties in this transition size regime lying between clusters and nanoparticles. Interestingly, an inflection point is observed for Au NPs smaller than 8 nm in which the sensitivity of the localized surface plasmon resonance (LSPR) peak position as a function of NPs size and surface modifications dramatically increase. These studies are relevant in the design of the final selectivity, activity and compatibility of Au NPs, especially in those (bio)applications where size is a critical parameter (e.g., biodistribution, multiplex labeling, and protein interaction). © 2016 American Chemical Society.

  • Tuning the Plasmonic Response up: Hollow Cuboid Metal Nanostructures

    Genç A., Patarroyo J., Sancho-Parramon J., Arenal R., Duchamp M., Gonzalez E.E., Henrard L., Bastús N.G., Dunin-Borkowski R.E., Puntes V.F., Arbiol J. ACS Photonics; 3 (5): 770 - 779. 2016. 10.1021/acsphotonics.5b00667. IF: 5.404

    We report the fine-tuning of the localized surface plasmon resonances (LSPRs) from ultraviolet to near-infrared by nanoengineering the metal nanoparticle morphologies from solid Ag nanocubes to hollow AuAg nanoboxes and AuAg nanoframes. Spatially resolved mapping of plasmon resonances by electron energy loss spectroscopy (EELS) revealed a homogeneous distribution of highly intense plasmon resonances around the hollow nanostructures and the interaction, that is, hybridization, of inner and outer plasmon fields for the nanoframe. Experimental findings are accurately correlated with the boundary element method (BEM) simulations demonstrating that the homogeneous distribution of the plasmon resonances is the key factor for their improved plasmonic properties. As a proof of concept for these enhanced plasmonic properties, we show the effective label free sensing of bovine serum albumin (BSA) of single-walled AuAg nanoboxes in comparison with solid Au nanoparticles, demonstrating their excellent performance for future biomedical applications. © 2016 American Chemical Society.


  • Enhanced reactivity of high-index surface platinum hollow nanocrystals

    González E., Merkoçi F., Arenal R., Arbiol J., Esteve J., Bastús N.G., Puntes V. Journal of Materials Chemistry A; 4 (1): 200 - 208. 2015. 10.1039/c5ta07504a. IF: 7.443

    The precise morphological control of the surface of inorganic nanocrystals (NCs) is critical for the understanding of the unique properties of the materials at the nanoscale and useful in a wide range of applications, such as catalysis, where the development of highly active and low-cost materials represents a landmark for the development of industrial technologies. Here we show how combining solid state chemistry and colloidal synthesis allows us to prepare exotic materials, in particular, PtAg@Pt single-crystal hollow NCs with high-index planes synthesized at room temperature by controlled corrosion of silver templates, which minimize Pt consumption and maximize surface reactivity. © The Royal Society of Chemistry 2016.

  • Exploring new synthetic strategies for the production of advanced complex inorganic nanocrystals

    Bastús N.G., Gonzalez E., Esteve J., Piella J., Patarroyo J., Merkoçi F., Puntes V. Zeitschrift fur Physikalische Chemie; 229 (1-2): 65 - 83. 2015. 10.1515/zpch-2014-0611. IF: 1.356

    The design of new protocols for the colloidal synthesis of complex nanocrystals (NCs) with advanced functionalities, comprising both hybrid and hollow structures, and the study of their fundamental properties is of paramount importance for the development of a new generation of nanostructured materials. The possibility of tailoring the dimensional regime of NCs, along with its composition and structure, represents a landmark achievement in the control of their unique physico-chemical properties. These properties, alongside with the ability to cheaply produce high quality NCs in fairly large amounts by wet-chemistry techniques, leads to their potential applicability from materials science to nanomedicine. Within this context, this review is focused on describing a successful framework for designing synthetic strategies for the production of advanced complex NCs, integrating the development of new synthetic methods with its structural characterization, monitoring of their properties, and study of its reactivity. As a result, it is expected to provide new routes to produce robust and easy-to-process NCs in a wide range of sizes, shapes and configurations that can be explored to achieve the combination of all degrees of control, aiming to produce a complete and diverse library of material combinations that will expand its applicability in a wide diversity of fields. © 2014 Walter de Gruyter Berlin/Boston.

  • SERS efficiencies of micrometric polystyrene beads coated with gold and silver nanoparticles: The effect of nanoparticle size

    Mir-Simon B., Morla-Folch J., Gisbert-Quilis P., Pazos-Perez N., Xie H.-N., Bastús N.G., Puntes V., Alvarez-Puebla R.A., Guerrini L. Journal of Optics (United Kingdom); 17 (11, 114012) 2015. 10.1088/2040-8978/17/11/114012. IF: 2.059

    Rapid advances in nanofabrication techniques of reproducibly manufacturing plasmonic substrates with well-defined nanometric scale features and very large electromagnetic enhancements paved the way for the final translation of the analytical potential of surface-enhanced Raman scattering (SERS) to real applications. A vast number of different SERS substrates have been reported in the literature. Among others, discrete particles consisting of an inorganic micrometric or sub-micrometric core homogeneously coated with plasmonic nanoparticles stand out for their ease of fabrication, excellent SERS enhancing properties, long-term optical stability and remarkable experimental flexibility (manipulation, storage etc). In this article, we performed a systematic experimental study of the correlation between the size of quasi-spherical gold and silver nanoparticle and the final optical property of their corresponding assembles onto micrometric polystyrene (PS) beads. The size and composition of nanoparticles play a key role in tuning the SERS efficiency of the hybrid material at a given excitation wavelength. This study provides valuable information for the selection and optimization of the appropriate PS@NPs substrates for the desired applications. © 2015 IOP Publishing Ltd.


  • Little Adjustments Significantly Improve the Turkevich Synthesis of Gold Nanoparticles

    Schulz, F.; Homolka, T.; Bastús, NG.; Puntes, V. F.; Weller,H.; Vossmeyer, T. Langmuir : the ACS journal of surfaces and colloids; 30 (35): 10779 - 10784. 2014. 10.1021/la503209b. IF: 4.384

  • Synthesis of highly monodisperse citrate-stabilized silver nanoparticles of up to 200 nm: Kinetic control and catalytic properties

    Bastús, N.G.; Merkoçi, F.; Piella, J.; Puntes, V. Chemistry of Materials; 26 (9): 2836 - 2846. 2014. 10.1021/cm500316k. IF: 8.535


  • Characterizing Nanoparticles Reactivity: Structure-Photocatalytic Activity Relationship

    Piella, J.; Bastús, N. G.; Casals, E.; Puntes, V. Journal of Physics: Conference Series; 429: 1. 2013. 10.1088/1742-6596/429/1/012040. IF: 0.000


  • Inorganic nanoparticles and the immune system: detection, selective activation and tolerance.

    Bastús, N.G.; Sánchez-Tilló, E.; Pujals, S.; Comenge, J.; Giralt, E.; Celada, A.; Lloberas, J.; Puntes, V.F. Proceedings of SPIE - The International Society for Optical Engineering; 823217: 1. 2012. 10.1117/12.917327.


  • Analysis of time-dependent conjugation of gold nanoparticles with an antiparkinsonian molecule by using curve resolution methods

    Amigo, J.M.; Bastús, N.G.; Hoen, R.; Vázquez-Campos, S.; Varón, M.; Royo, M.; Puntes, V.F. Analytica Chimica Acta; 2011. .

  • Influence of the Sequence of the Reagents Addition in the Citrate-Mediated Synthesis of Gold Nanoparticles

    Ojea-Jiménez, I.; Bastús, N.G.; Puntes, V.F. Journal of Physical Chemistry C; 2011. 10.1021/jp2017242.

  • Kinetically Controlled Seeded Growth Synthesis of Citrate-Stabilized Gold Nanoparticles of up to 200 nm: Size Focusing versus Ostwald Ripening

    Bastús, N.G.; Comenge, J.; Puntes, V.F. Langmuir : the ACS journal of surfaces and colloids; 2011. .


  • Small gold nanoparticles synthesized with sodium citrate and heavy water: Insights into the reaction mechanism

    Ojea-Jiménez, I.; Romero, F.M.; Bastús, N.G.; Puntes, V. Journal of Physical Chemistry C; 114: 1800 - 1804. 2010. 10.1021/jp9091305.


  • Homogeneous Conjugation of Peptides onto Gold Nanoparticles Enhances Macrophage Response

    Bastús, N. G.; Sánchez-Tillo, E.; Pujals, S.; Farrera, C.; López, C. ; Giralt, E. ; Celanda, A. ; Lloberas, J.; Puntes, V. ACS Nano; 3 (6): 1335 - 1344. 2009. 10.1021/nn8008273 CCC: $40.75.

  • Inorganic engineered nanoparticles and their impact on the immune response

    Sperling, R. A.; Casals, E.; Comenge, J.; Bastús, N. G. ; Puntes, V. Current Drug Metabolism; 10: 895 - 904. 2009.

  • Peptides conjugated to gold nanoparticles induce macrophage activation

    Bastús, N. G.; Sánchez-Tillo, E.; Pujals, S.; Farrera, C.; Kogan, M. J.; Giralt, E.; Celada, A.; Lloberas, J.; Puntes, V. F. Molecular Immunology; 46 (4): 743 - 748. 2009. 10.1016/j.molimm.2008.08.277 .

  • Shuttling Gold Nanoparticles into Tumoral Cells with an Amphipathic Proline-Rich Peptide

    Pujals, S. ; Bastus, N. G.; Pereiro, E.; López-Iglesias, C.; Puntes, V. F.; Kogan, M. J.; Giralt, E. Chemistry: a European Journal; 10 (6): 1025 - 1031. 2009. 10.1002/cbic.200800843 .


  • Distribution and potential toxicity of engineered inorganic nanoparticles and carbon nanostructures in biological systems

    Casals E.; Vazquez-Campos S.; Bastus N.G.; Puntes V. TrAC - Trends in Analytical Chemistry; 27 (8): 672 - 683. 2008. 10.1016/j.trac.2008.06.004.

  • Gold Nanoparticles and Microwave Irradiation Inhibit Beta-Amyloid Amyloidogenesis

    Araya Eyleen; Olmedo Ivonne; Bastus Neus G.; Guerrero Simon; Puntes Victor F.; Giralt Ernest; Kogan Marcelo J Nanoscale Research Letters; 3 (11): 435 - 443. 2008. 10.1007/s11671-008-9178-5.

  • Reactivity of engineered inorganic nanoparticles and carbon nanostructures in biological media

    Neus G. Bastús; Eudald Casals; Socorro Vázquez-Campos; Victor Puntes Nanotoxicology; 2 (3): 99 - 112. 2008. 10.1080/17435390802217830.

  • Shuttling Gold Nanoparticles into Tumoral Cells with an Amphipathic Pro rich Peptide

    Pujals S; Bastús NG; Pereiro E; López-Iglesias E; Puntes VF; Kogan MJ; Giralt E Chemistry: a European Journal; 10: 1025 - 1031. 2008. 10.1002/cbic.200800843.