Staff directory Olalla Calvo Lozano



  • Using Electrochemical Immunoassay in a Novel Microtiter Plate to Detect Surface Markers of Preeclampsia on Urinary Extracellular Vesicles

    Lee, S; Gonzalez-Suarez, AM; Huang, XH; Calvo-Lozano, O; Suvakov, S; Lechuga, LM; Garovic, VD; Stybayeva, G; Revzin, A Acs Sensors; 8 (1): 207 - 217. 2023. 10.1021/acssensors.2c02077.


  • Coating Bioactive Microcapsules with Tannic Acid Enhances the Phenotype of the Encapsulated Pluripotent Stem Cells

    Choi D., Gwon K., Hong H.J., Baskaran H., Calvo-Lozano O., Gonzalez-Suarez A.M., Park K., De Hoyos-Vega J.M., Lechuga L.M., Hong J., Stybayeva G., Revzin A. ACS Applied Materials and Interfaces; 14 (23): 27274 - 27286. 2022. 10.1021/acsami.2c06783.

    Human pluripotent stem cells (hPSCs) may be differentiated into any adult cell type and therefore hold incredible promise for cell therapeutics and disease modeling. There is increasing interest in three-dimensional (3D) hPSC culture because of improved differentiation outcomes and potential for scale up. Our team has recently described bioactive heparin (Hep)-containing core-shell microcapsules that promote rapid aggregation of stem cells into spheroids and may also be loaded with growth factors for the local and sustained delivery to the encapsulated cells. In this study, we explored the possibility of further modulating bioactivity of microcapsules through the use of an ultrathin coating composed of tannic acid (TA). Deposition of the TA film onto model substrates functionalized with Hep and poly(ethylene glycol) was characterized by ellipsometry and atomic force microscopy. Furthermore, the presence of the TA coating was observed to increase the amount of basic fibroblast growth factor (bFGF) incorporation by up to twofold and to extend its release from 5 to 7 days. Most significantly, TA-microcapsules loaded with bFGF induced higher levels of pluripotency expression compared to uncoated microcapsules containing bFGF. Engineered microcapsules described here represent a new stem cell culture approach that enables 3D cultivation and relies on local delivery of inductive cues. © 2022 American Chemical Society. All rights reserved.

  • Label-Free Plasmonic Biosensor for Rapid, Quantitative, and Highly Sensitive COVID-19 Serology: Implementation and Clinical Validation

    Calvo-Lozano O., Sierra M., Soler M., Estévez M.C., Chiscano-Camón L., Ruiz-Sanmartin A., Ruiz-Rodriguez J.C., Ferrer R., González-López J.J., Esperalba J., Fernández-Naval C., Bueno L., López-Aladid R., Torres A., Fernández-Barat L., Attoumani S., Charrel R., Coutard B., Lechuga L.M. Analytical Chemistry; 94 (2): 975 - 984. 2022. 10.1021/acs.analchem.1c03850. IF: 6.986

    Serological tests are essential for the control and management of COVID-19 pandemic (diagnostics and surveillance, and epidemiological and immunity studies). We introduce a direct serological biosensor assay employing proprietary technology based on plasmonics, which offers rapid (<15 min) identification and quantification of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies in clinical samples, without signal amplification. The portable plasmonic device employs a custom-designed multiantigen (RBD peptide and N protein) sensor biochip and reaches detection limits in the low ng mL–1 range employing polyclonal antibodies. It has also been implemented employing the WHO-approved anti-SARS-CoV-2 immunoglobulin standard. A clinical validation with COVID-19 positive and negative samples (n = 120) demonstrates its excellent diagnostic sensitivity (99%) and specificity (100%). This positions our biosensor as an accurate and easy-to-use diagnostics tool for rapid and reliable COVID-19 serology to be employed both at laboratory and decentralized settings for the disease management and for the evaluation of immunological status during vaccination or treatment. © 2021 The Authors. Published by American Chemical Society

  • One-Step and Real-Time Detection of microRNA-21 i n Human Samples for Lung Cancer Biosensing Diagnosis

    Calvo-Lozano, O; Garcia-Aparicio, P; Raduly, LZ; Estevez, MC; Berindan-Neagoe, I; Ferracin, M; Lechuga, LM Analytical Chemistry; 94 (42): 14659 - 14665. 2022. 10.1021/acs.analchem.2c02895. IF: 8.008


  • Fast and accurate pneumocystis pneumonia diagnosis in human samples using a label-free plasmonic biosensor

    Calvo-Lozano O., Aviñó A., Friaza V., Medina-Escuela A., Huertas C.S., Calderón E.J., Eritja R., Lechuga L.M. Nanomaterials; 10 (6, 1246): 1 - 18. 2020. 10.3390/NANO10061246. IF: 4.324

    Pneumocystis jirovecii is a fungus responsible for human Pneumocystis pneumonia, one of the most severe infections encountered in immunodepressed individuals. The diagnosis of Pneumocystis pneumonia continues to be challenging due to the absence of specific symptoms in infected patients. Moreover, the standard diagnostic method employed for its diagnosis involves mainly PCR-based techniques, which besides being highly specific and sensitive, require specialized personnel and equipment and are time-consuming. Our aim is to demonstrate an optical biosensor methodology based on surface plasmon resonance to perform such diagnostics in an efficient and decentralized scheme. The biosensor methodology employs poly-purine reverse-Hoogsteen hairpin probes for the detection of the mitochondrial large subunit ribosomal RNA (mtLSU rRNA) gene, related to P. jirovecii detection. The biosensor device performs a real-time and label-free identification of the mtLSU rRNA gene with excellent selectivity and reproducibility, achieving limits of detection of around 2.11 nM. A preliminary evaluation of clinical samples showed rapid, label-free and specific identification of P. jirovecii in human lung fluids such as bronchoalveolar lavages or nasopharyngeal aspirates. These results offer a door for the future deployment of a sensitive diagnostic tool for fast, direct and selective detection of Pneumocystis pneumonia disease. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.

  • Nanophotonic biosensors: Driving personalized medicine

    Soler M., Calvo-Lozano O., Carmen Estevez M., Lechuga L.M. Optics and Photonics News; 31 (4): 25 - 31. 2020. 10.1364/OPN.31.4.000024. IF: 0.000

    [No abstract available]


  • Advanced Evanescent-Wave Optical Biosensors for the Detection of Nucleic Acids: An Analytic Perspective

    Huertas C.S., Calvo-Lozano O., Mitchell A., Lechuga L.M. Frontiers in Chemistry; 7 (724) 2019. 10.3389/fchem.2019.00724. IF: 3.782

    Evanescent-wave optical biosensors have become an attractive alternative for the screening of nucleic acids in the clinical context. They possess highly sensitive transducers able to perform detection of a wide range of nucleic acid-based biomarkers without the need of any label or marker. These optical biosensor platforms are very versatile, allowing the incorporation of an almost limitless range of biorecognition probes precisely and robustly adhered to the sensor surface by covalent surface chemistry approaches. In addition, their application can be further enhanced by their combination with different processes, thanks to their integration with complex and automated microfluidic systems, facilitating the development of multiplexed and user-friendly platforms. The objective of this work is to provide a comprehensive synopsis of cutting-edge analytical strategies based on these label-free optical biosensors able to deal with the drawbacks related to DNA and RNA detection, from single point mutations assays and epigenetic alterations, to bacterial infections. Several plasmonic and silicon photonic-based biosensors are described together with their most recent applications in this area. We also identify and analyse the main challenges faced when attempting to harness this technology and how several innovative approaches introduced in the last years manage those issues, including the use of new biorecognition probes, surface functionalization approaches, signal amplification and enhancement strategies, as well as, sophisticated microfluidic solutions. © Copyright © 2019 Huertas, Calvo-Lozano, Mitchell and Lechuga.

  • Early sepsis diagnosis via protein and miRNA biomarkers using a novel point-of-care photonic biosensor

    Fabri-Faja N., Calvo-Lozano O., Dey P., Terborg R.A., Estevez M.-C., Belushkin A., Yesilköy F., Duempelmann L., Altug H., Pruneri V., Lechuga L.M. Analytica Chimica Acta; 1077: 232 - 242. 2019. 10.1016/j.aca.2019.05.038. IF: 5.256

    Sepsis is a condition characterized by a severe stage of blood-infection often leading to tissue damage, organ failure and finally death. Fast diagnosis and identification of the sepsis stage (sepsis, severe sepsis or septic shock) is critical for the patient's evolution and could help in defining the most adequate treatment in order to reduce its mortality. The combined detection of several biomarkers in a timely, specific and simultaneous way could ensure a more accurate diagnosis. We have designed a new optical point-of-care (POC) device based on a phase-sensitive interferometric biosensor with a label-free microarray configuration for potential high-throughput evaluation of specific sepsis biomarkers. The sensor chip, which relies on the use of metallic nanostructures, provides versatility in terms of biofunctionalization, allowing the efficient immobilization of different kind of receptors such as antibodies or oligonucleotides. We have focused on two structurally different types of biomarkers: proteins, including C-reactive protein (CRP) and Interleukin 6 (IL6), and miRNAs, using miRNA-16 as an example. Limits of Detection (LoD) of 18 μg mL−1, 88 μg mL−1 and 1 μM (6 μg mL−1) have been respectively obtained for CRP, IL6 and miRNA-16 in individual assays, with high accuracy and reproducibility. The multiplexing capabilities have also been assessed with the simultaneous analysis of both protein biomarkers. © 2019 Elsevier B.V.

  • Label-free Bacteria Quantification in Blood Plasma by a Bioprinted Microarray Based Interferometric Point-of-Care Device

    Dey P., Fabri-Faja N., Calvo-Lozano O., Terborg R.A., Belushkin A., Yesilkoy F., Fàbrega A., Ruiz-Rodriguez J.C., Ferrer R., González-López J.J., Estévez M.C., Altug H., Pruneri V., Lechuga L.M. ACS Sensors; 4 (1): 52 - 60. 2019. 10.1021/acssensors.8b00789. IF: 6.944

    Existing clinical methods for bacteria detection lack speed, sensitivity, and, importantly, point-of-care (PoC) applicability. Thus, finding ways to push the sensitivity of clinical PoC biosensing technologies is crucial. Here we report a portable PoC device based on lens-free interferometric microscopy (LIM). The device employs high performance nanoplasmonics and custom bioprinted microarrays and is capable of direct label-free bacteria (E. coli) quantification. With only one-step sample handling we offer a sample-to-data turnaround time of 40 min. Our technology features detection sensitivity of a single bacterial cell both in buffer and in diluted blood plasma and is intrinsically limited by the number of cells present in the detection volume. When employed in a hospital setting, the device has enabled accurate categorization of sepsis patients (infectious SIRS) from control groups (healthy individuals and noninfectious SIRS patients) without false positives/negatives. User-friendly on-site bacterial clinical diagnosis can thus become a reality. © 2018 American Chemical Society.

  • Label-Free Nanoplasmonic Biosensing of Cancer Biomarkers for Clinical Diagnosis

    Portela A., Peláez E.C., Calvo-Lozano O., Estévez M.C., Lechuga L.M. Methods in Molecular Biology; 2027: 115 - 140. 2019. 10.1007/978-1-4939-9616-2_10.

    Biosensing of cancer biomarkers enabling early diagnosis of cancer constitutes an essential tool for clinical intervention and application of novel therapies against cancer disease. Optical biosensor instruments as point-of-care (POC) devices and operating under label-free scheme have demonstrated to provide fast, simple, and high-sensitivity assays even at home care environment. Nanoplasmonic biosensors are thought to be a powerful tool for detection of complex analytes of relevant clinical applications. Using high-throughput fabrication techniques, large surface patterned with gold nanodisk structures is obtained showing surface sensitivities with limit of detection (LOD) in the order of picomolar concentration range. Here, we describe two major assay methodologies used for detection of lung and colorectal cancer, respectively. Particularly, we have selected a complementary hybridization DNA/RNA assay for the assessment of two miRNAs (miRNA-210 and miRNA-205) for detection of lung cancer. However, for colorectal cancer we present the detection of four tumor-associated antigen (TAA) biomarkers (MAPKAPK3, PIM-1, STK4, and GTF2B) as possible TAA targets for autoantibody production. Strategies for detecting these biomarkers in real samples such as serum are also presented, demonstrating the capabilities of these assays to be transferred to real clinical settings. © Springer Science+Business Media, LLC, part of Springer Nature 2019.

  • Label-free, scalable and point-of-care imaging platform for rapid analysis of biomarker

    L. Duempelmann, R. A. Terborg, J. Pello, I. Mannelli, F. Yesilkoy, A. A. Belushkin, Y. Jahani, N. Fabri-Faja, P. Dey, O. Calvo-Lozano, M. -. Estevez, A. Fàbrega, J. J. González-López, L. M. Lechuga, H. Altug, and V. Pruneri SPIE Proceedings (Optical Society of America, 2019); Clinical and Preclinical Optical Diagnostics II, V 2019. 10.1117/12.2525878.

    We propose a disruptive point-of-care (PoC) imaging platform based on lens-free interference phase-contrast imaging for rapid detection of biomarker such as for sepsis and potentially other diseases (e.g. cancer). It enables simultaneous analysis of potentially up to 10,000 functionalized microarray spots with different biomarkers with fast time-to-results (few minutes) and by consuming a small sample volume (~10 µL). The high sensitivity allows direct measurements of the biomarker binding without the use of fluorescent labels (e.g. ELISA) or microbial culture methods. In addition, ad-hoc plasmonic nano-structuring is utilized to significantly improve the sensitivity for biomarker detection (optical path difference ~Å) to concentration levels relevant for disease diagnosis. The proposed technology incorporates a portable and low-cost lens-free imaging reader made of consumer electronic components, plasmonic microarrays with distinct functionalization, and user-friendly software based on a novel phase-shifting interferometry method for topography and refractive index analysis. Due to its compactness and cost-efficiency, we foresee a great potential for PoC applications, especially for the rapid detection of infectious diseases or life-threatening conditions, e.g. sepsis, but also for clinical trials of drugs and food control.


  • A CO2 optical sensor based on self-assembled metal-organic framework nanoparticles

    Chocarro-Ruiz B., Pérez-Carvajal J., Avci C., Calvo-Lozano O., Alonso M.I., Maspoch D., Lechuga L.M. Journal of Materials Chemistry A; 6 (27): 13171 - 13177. 2018. 10.1039/c8ta02767f. IF: 9.931

    The development of devices for sensing and monitoring CO2 levels is crucial for many fields such as food packaging and for human safety indoors. Herein the fabrication of an optical CO2 sensor by integration of a metal-organic framework (MOF) onto bimodal optical waveguides is reported. This sensor is constructed via self-assembly of a transparent film of zeolitic imidazolate framework-8 (ZIF-8) nanoparticles (size: 32 ± 5 nm) on the waveguides. The nanoZIF-8-based sensor exhibits a broad linear response, with limits of detection of 3130 ppm at room temperature and 774 ppm at 278 K. Furthermore, it is robust, selective, fast and reusable, and can be stored under humid conditions with no loss in performance. © The Royal Society of Chemistry 2018.