Molding with nanoparticle-based one-dimensional photonic crystals: A route to flexible and transferable Bragg mirrors of high dielectric contrast

Self-standing, flexible Bragg mirror films of high refractive index contrast and showing intense and wide Bragg peaks are herein presented. Nanoparticle-based one-dimensional photonic crystals are used as templates to infiltrate a polymer, which provides the multilayer with mechanical stability while preserving the dielectric contrast existing in the mold. Such films can be lifted off the substrate and used to coat another surface of arbitrary shapeMinisterio de Ciencia y Educación MAT2008-02166Junta de Andalucía FQM-357

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

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

Optical nanogap antennas as plasmonic biosensors for the detection of miRNA biomarkers

Nanoplasmonic biosensors based on nanogap antenna structures usually demand complex and expensive fabrication processes in order to achieve a good performance and sensitive detection. We here report the fabrication of large-area nanoplasmonic sensor chips based on nanogap antennas by employing a customized, simple and low-cost colloidal lithography process. By precisely controlling the angle for tilted e-beam metal evaporation, an elliptical mask is produced, which defines the total length of the dipole antenna nanostructures while assuring that the plasmonic response is oriented in the same direction along the sensor chip. Large-area sensor chips of nanogap antennas formed by pairs of gold nanodisks separated by gaps with an average size of 11.6 ± 4.7 nm are obtained. The optical characterization of the nanogap antenna structures in an attenuated total reflection (ATR) configuration shows a bulk refractive index sensitivity of 422 nm per RIU, which is in agreement with FDTD numerical simulations. The biosensing potential of the cm-sized nanostructured plasmonic sensor chips has been evaluated for the detection of miRNA-210, a relevant biomarker for lung cancer diagnosis, through a DNA/miRNA hybridization assay. A limit of detection (LOD) of 0.78 nM (5.1 ng mL) was achieved with no need of further amplification steps, demonstrating the high sensitivity of these plasmonic nanogap antennas for the direct and label-free detection of low molecular weight biomolecules such as miRNAs

Environmentally responsive nanoparticle-based luminescent optical resonators

In this work, we demonstrate that optical resonators built using all-nanoparticle-based porous building blocks provide a responsive multifunctional matrix, totally different emission spectra being attained from the same embedded luminescent nanophosphors under varying environmental conditions. We show a clear correlation between modifications in the ambient surroundings, the induced changes of the resonant modes, and the resulting variations in the emission response. The method is versatile and allows nanophosphors of arbitrary shape to be integrated in the cavity. By precise control of the spectral features of the optical resonances, luminescence is strongly modulated in selected and tuneable wavelength ranges. Applications in the fields of sensing and detection are foreseen for these materialsEspaña Ministerio de Ciencia e Innovación MAT2008-02166 CONSOLIDER HOPE CSD2007-00007Junta de Andalucía FQM357

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

The development of devices for sensing and monitoring CO levels is crucial for many fields such as food packaging and for human safety indoors. Herein the fabrication of an optical CO 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

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

COVID-19; Biosensor plasmónico; SerologíaCOVID-19; Biosensor plasmònic; SerologiaCOVID-19; Plasmonic biosensor; SerologySerological 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.ICN2 and UVE acknowledge financial support from H2020 Research and Innovation Programme of the European Commission (H202-SC1-PHE-Coronavirus-2020, CONVAT Project, No. 101003544). The ICN2 is funded by the CERCA program/Generalitat de Catalunya and supported by the Severo Ochoa Centres of Excellence program funded by the Spanish Research Agency (AEI, grant no. SEV-2017-0706). ICN2 group is very grateful to EPI Industries (Barcelona, Spain) for its kind donation supporting our research in COVID-19. O.C.-L. acknowledges the economic support from the Spanish Ministry of Science and Innovation and the Spanish Research Agency and the European Social Fund (ESF) (ref. BES-2017-080527) linked to the TEC 2016-78515-R project Predict. A part of the work was supported by the European Virus Archive GLOBAL (EVA-GLOBAL) project that has received funding from the EU Horizon 2020 (grant agreement No. 871029). A.T. and L.F.-B. acknowledge financial support from GENCAT-DGRIS COVID. We are indebted to all the patients who accepted to participate contributing to science advancement. We are indebted to the HCB-IDIBAPS Biobank for the human samples and data procurement and to the Fundació Glòria Soler for its support to the COVIDBANK collection. We thank the IDIBAPS Biobank for its valuable contribution to sample processing and storage. The authors acknowledge the EU Horizon 2020 Program under grant agreement no. 644956 (RAIS project) for funding the Hospital Vall d’Hebron Biobank. The VHIR-HUVH is supported by Plan Nacional de I + D + i 2013-2016 and ISCIII-Ministerio de Ciencia e Innovación, and Spanish Network for Research in Infectious Diseases (REIPI RD16/0016/0003)─cofinanced by European Development Regional Fund “A way to achieve Europe,” Operative program Intelligent Growth 2014. Part of the samples and data from patients included in this study were provided by the Vall d’Hebron University Hospital Biobank (PT17/0015/0047), integrated in the Spanish National Biobanks Network, and they were processed following standard operating procedures with the appropriate approval of the Ethical and Scientific Committee. The authors kindly appreciate the generous donation of samples and clinical data of the donors of the Sepsis Bank of HUVH Biobank and COVID-19 patients attended at HUVH

Label-free plasmonic biosensor for rapid, quantitative, and highly sensitive COVID-19 serology: implementation and clinical validation

Serological tests are essential for the control and management of COVID-19 pandemic, not only for current and historical diagnostics but especially for surveillance, epidemiological, and acquired immunity studies. Clinical COVID-19 serology is routinely performed by enzymatic or chemiluminescence immunoassays (i.e., ELISA or CLIA), which provide good sensitivities at the expense of relatively long turnaround times and specialized laboratory settings. Rapid serological tests, based on lateral flow assays, have also been developed and widely commercialized, but they suffer from limited reliability due to relatively low sensitivity and specificity. We have developed and validated a direct serological biosensor assay employing proprietary technology based on Surface Plasmon Resonance (SPR). The biosensor offers a rapid -less than 15 min- identification and quantification of SARS-CoV-2 antibodies directly in clinical samples, without the need of any signal amplification. The portable plasmonic biosensor device employs a custom-designed multi-antigen sensor biochip, combining the two main viral antigens (RBD peptide and N protein), for simultaneous detection of human antibodies targeting both antigens. The SPR serology assay reaches detection limits in the low ng mL-1 range employing polyclonal antibodies as standard, which are well below the commonly detected antibody levels in COVID-19 patients. The assay has also been implemented employing the first WHO approved anti-SARS-CoV-2 immunoglobulin standard. We have carried out a clinical validation with COVID-19 positive and negative samples (n=120) that demonstrates the excellent diagnostic sensitivity (99%) and specificity (100%). This positions our biosensor device as an accurate, robust, and easy-to-use diagnostics tool for rapid and reliable COVID-19 serology to be employed both at laboratory and decentralized settings for the management of COVID-19 patients and for the evaluation of immunological status during vaccination, treatment or in front of emerging variants.H2020 Research and Innovation Programme of the European Commission Project, No. 101003544 Spanish Research Agency (AEI, grant no. SEV-2017-0706AEI, grant no. SEV-2017-0706) Spanish Ministry of Science and Innovation and the Spanish Research Agency and the European Social Fund (ESF)BES-2017-080527 GENCAT-DGRIS COVID EU H2020 Programme (644956) Plan Nacional de I+D+i 2013-2016 ISCIII- Ministerio de Ciencia e Innovación, Vall d’Hebron University Hospital Biobank PT17/0015/0047 European Virus Archive GLOBAL (EVA-GLOBAL) EU Horizon 2020 (grant agreement No. 871029) Fundació Glòria Soler for COVIDBANK collection Spanish Network for Research in Infectious Diseases (REIPI RD16/0016/0003)N

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

15 pages. -- Content: 1. Supplementary text: 1.1.Chemical and biological reagents; 1.2.SPR biosensor device; 1.3.Plasmonic sensor chip preparation; 1.4.Clinical samples collection; 1.5.Stratification of convalescent COVID patients. Samples collection from Clinic Hospital (Barcelona); 1.6. Standard analytical techniques (ELISA, CLIA and LFA); 1.7.Data analysis; 1.8.Diagnostic sensitivity and specificity. -- 2. Figures. -- Tables S1-S3. -- References.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.Peer reviewe

Nanophotonic point-of-care biosensors for innovative clinical diagnosis of respiratory diseases

Els mètodes convencionals per al diagnòstic de les malalties respiratòries es basen principalment en les proves clíniques per imatge. Complementar aquesta anàlisi amb una avaluació molecular pot proporcionar un diagnòstic més adequat i complet. No obstant això, les tècniques moleculars impliquen llargs temps d’espera i sofisticades tècniques i instal·lacions. Aquesta Tesi Doctoral té com a objectiu principal oferir avançats biosensores basats en ones evanescents com una interessant alternativa per al diagnòstic clínic de diverses malalties respiratòries. Hem implementat un biosensor de ressonància de plasmó superficial (SPR) i un biosensor interferomètric de guia d’ona bimodal (BiMW), que ofereixen una anàlisi directa, sensible i ràpid de biomarcadors específics utilitzant un volum de mostra reduït. El seu potencial d’integració en les plataformes analítiques de point-of-care (POC) els situa com a excel·lents tecnologies per a un diagnòstic més eficaç de les malalties. Al llarg de la tesi, s’han dissenyat i implementat diverses metodologies de biosensores que permeten la detecció directa de biomarcadors relacionats amb el pulmó en fluids biològics. La immobilització del biorreceptor, les propietats antifouling de la capa de biorreconeixement i la detecció dels biomarcadors s’han optimitzat i avaluat en termes de sensibilitat, especificitat i reproductibilitat. En aquesta Tesi, hem desenvolupat: (i) un assaig serològic ràpid i quantitatiu per a la detecció d’anticossos anti-SARS-CoV-2; (ii) un assaig genètic sense amplificació per a la identificació de Pneumocystis pneumonia en mostres respiratòries; i (iii) un enfocament nou per a la detecció precoç del càncer de pulmó basat en un panell de biomarcadors que combina anàlits proteics i epigenètics presents en el plasma humà. El treball d’aquesta tesi ha obert la porta a enfocaments analítics innovadors per al diagnòstic de trastorns relacionats amb el pulmó, superant algunes de les limitacions de les tècniques analítiques convencionals i mostrant un enorme potencial per a la seva implementació en dispositius POC aplicables en la pràctica clínica real.Los métodos convencionales para el diagnóstico de las enfermedades respiratorias se basan principalmente en las pruebas clínicas por imagen. Complementar este análisis con una evaluación molecular puede proporcionar un diagnóstico más adecuado y completo. Sin embargo, las técnicas moleculares implican largos tiempos de espera y sofisticadas técnicas e instalaciones. Esta Tesis Doctoral tiene como objetivo principal ofrecer avanzados biosensores basados en ondas evanescentes como una interesante alternativa para el diagnóstico clínico de diversas enfermedades respiratorias. Hemos implementado un biosensor de resonancia de plasmón superficial (SPR) y un biosensor interferométrico de guía de onda bimodal (BiMW), que ofrecen un análisis directo, sensible y rápido de biomarcadores específicos utilizando un volumen de muestra reducido. Su potencial de integración en las plataformas analíticas de point-of-care (POC) los sitúa como excelentes tecnologías para un diagnóstico más eficaz de las enfermedades. A lo largo de la tesis, se han diseñado e implementado varias metodologías de biosensores que permiten la detección directa de biomarcadores relacionados con el pulmón en fluidos biológicos. La inmovilización del biorreceptor, las propiedades antifouling de la capa de biorreconocimiento y la detección de los biomarcadores se han optimizado y evaluado en términos de sensibilidad, especificidad y reproducibilidad. En esta Tesis, hemos desarrollado: (i) un ensayo serológico rápido y cuantitativo para la detección de anticuerpos anti-SARS-CoV-2; (ii) un ensayo genético sin amplificación para la identificación de Pneumocystis pneumonia en muestras respiratorias; y (iii) un enfoque novedoso para la detección temprana del cáncer de pulmón basado en un panel de biomarcadores que combina analitos proteicos y epigenéticos presentes en el plasma humano. El trabajo de esta tesis ha abierto la puerta a enfoques analíticos innovadores para el diagnóstico de trastornos relacionados con el pulmón, superando algunas de las limitaciones de las técnicas analíticas convencionales y mostrando un enorme potencial para su implementación en dispositivos POC aplicables en la práctica clínica real.The conventional methods for the diagnosis of respiratory diseases rely mainly on the clinical evidence by imaging. Complementing such analysis with a molecular evaluation can provide a more suitable and exhaustive diagnosis. However, all these technologies imply long times-to-result and sophisticated techniques and laboratories. This Doctoral Thesis has as main objective to offer novel evanescent wave-based biosensors as a valuable alternative solution for the clinical diagnosis of several respiratory diseases. We have implemented a surface plasmon resonance biosensor (SPR) and a bimodal waveguide (BiMW) interferometric biosensor, which both offer direct, sensitive, and rapid analysis of specific biomarkers using a reduce sample volume. Their potential for integration into point-of-care (POC) analytical platforms positions them as excellent technologies for a more effective disease diagnosis. Along the Thesis, several biosensor methodologies have been designed and implemented allowing the direct detection of lung-related biomarkers in biological fluids. Bioreceptor immobilisation, antifouling properties of the bioreceptor layer and biomarkers detection have been optimised and evaluated in terms of sensitivity, specificity and reproducibility. In this Thesis, we have developed: (i) a rapid and quantitative serological assay for the detection of anti-SARS-CoV-2 antibodies; (ii) an amplification-free genetic assay for Pneumocystis pneumonia identification in respiratory specimens; and (iii) a novel approach to the early detection of lung cancer based on a biomarker panel combining protein and epigenetic analytes present in human plasma. The work in this thesis has opened the door to innovative analytical approaches for the diagnosis of lung-related disorders, overcoming some of the limitations of the conventional analytical techniques and exhibiting an enormous potential for their implementation in POC devices applicable in the real clinical practice.Universitat Autònoma de Barcelona. Programa de Doctorat en Biotecnologi

Nanophotonic point-of-care biosensors for innovative clinical diagnosis of respiratory diseases

Els mètodes convencionals per al diagnòstic de les malalties respiratòries es basen principalment en les proves clíniques per imatge. Complementar aquesta anàlisi amb una avaluació molecular pot proporcionar un diagnòstic més adequat i complet. No obstant això, les tècniques moleculars impliquen llargs temps d'espera i sofisticades tècniques i instal·lacions. Aquesta Tesi Doctoral té com a objectiu principal oferir avançats biosensores basats en ones evanescents com una interessant alternativa per al diagnòstic clínic de diverses malalties respiratòries. Hem implementat un biosensor de ressonància de plasmó superficial (SPR) i un biosensor interferomètric de guia d'ona bimodal (BiMW), que ofereixen una anàlisi directa, sensible i ràpid de biomarcadors específics utilitzant un volum de mostra reduït. El seu potencial d'integració en les plataformes analítiques de point-of-care (POC) els situa com a excel·lents tecnologies per a un diagnòstic més eficaç de les malalties. Al llarg de la tesi, s'han dissenyat i implementat diverses metodologies de biosensores que permeten la detecció directa de biomarcadors relacionats amb el pulmó en fluids biològics. La immobilització del biorreceptor, les propietats antifouling de la capa de biorreconeixement i la detecció dels biomarcadors s'han optimitzat i avaluat en termes de sensibilitat, especificitat i reproductibilitat. En aquesta Tesi, hem desenvolupat: (i) un assaig serològic ràpid i quantitatiu per a la detecció d'anticossos anti-SARS-CoV-2; (ii) un assaig genètic sense amplificació per a la identificació de Pneumocystis pneumonia en mostres respiratòries; i (iii) un enfocament nou per a la detecció precoç del càncer de pulmó basat en un panell de biomarcadors que combina anàlits proteics i epigenètics presents en el plasma humà. El treball d'aquesta tesi ha obert la porta a enfocaments analítics innovadors per al diagnòstic de trastorns relacionats amb el pulmó, superant algunes de les limitacions de les tècniques analítiques convencionals i mostrant un enorme potencial per a la seva implementació en dispositius POC aplicables en la pràctica clínica real.Los métodos convencionales para el diagnóstico de las enfermedades respiratorias se basan principalmente en las pruebas clínicas por imagen. Complementar este análisis con una evaluación molecular puede proporcionar un diagnóstico más adecuado y completo. Sin embargo, las técnicas moleculares implican largos tiempos de espera y sofisticadas técnicas e instalaciones. Esta Tesis Doctoral tiene como objetivo principal ofrecer avanzados biosensores basados en ondas evanescentes como una interesante alternativa para el diagnóstico clínico de diversas enfermedades respiratorias. Hemos implementado un biosensor de resonancia de plasmón superficial (SPR) y un biosensor interferométrico de guía de onda bimodal (BiMW), que ofrecen un análisis directo, sensible y rápido de biomarcadores específicos utilizando un volumen de muestra reducido. Su potencial de integración en las plataformas analíticas de point-of-care (POC) los sitúa como excelentes tecnologías para un diagnóstico más eficaz de las enfermedades. A lo largo de la tesis, se han diseñado e implementado varias metodologías de biosensores que permiten la detección directa de biomarcadores relacionados con el pulmón en fluidos biológicos. La inmovilización del biorreceptor, las propiedades antifouling de la capa de biorreconocimiento y la detección de los biomarcadores se han optimizado y evaluado en términos de sensibilidad, especificidad y reproducibilidad. En esta Tesis, hemos desarrollado: (i) un ensayo serológico rápido y cuantitativo para la detección de anticuerpos anti-SARS-CoV-2; (ii) un ensayo genético sin amplificación para la identificación de Pneumocystis pneumonia en muestras respiratorias; y (iii) un enfoque novedoso para la detección temprana del cáncer de pulmón basado en un panel de biomarcadores que combina analitos proteicos y epigenéticos presentes en el plasma humano. El trabajo de esta tesis ha abierto la puerta a enfoques analíticos innovadores para el diagnóstico de trastornos relacionados con el pulmón, superando algunas de las limitaciones de las técnicas analíticas convencionales y mostrando un enorme potencial para su implementación en dispositivos POC aplicables en la práctica clínica real.The conventional methods for the diagnosis of respiratory diseases rely mainly on the clinical evidence by imaging. Complementing such analysis with a molecular evaluation can provide a more suitable and exhaustive diagnosis. However, all these technologies imply long times-to-result and sophisticated techniques and laboratories. This Doctoral Thesis has as main objective to offer novel evanescent wave-based biosensors as a valuable alternative solution for the clinical diagnosis of several respiratory diseases. We have implemented a surface plasmon resonance biosensor (SPR) and a bimodal waveguide (BiMW) interferometric biosensor, which both offer direct, sensitive, and rapid analysis of specific biomarkers using a reduce sample volume. Their potential for integration into point-of-care (POC) analytical platforms positions them as excellent technologies for a more effective disease diagnosis. Along the Thesis, several biosensor methodologies have been designed and implemented allowing the direct detection of lung-related biomarkers in biological fluids. Bioreceptor immobilisation, antifouling properties of the bioreceptor layer and biomarkers detection have been optimised and evaluated in terms of sensitivity, specificity and reproducibility. In this Thesis, we have developed: (i) a rapid and quantitative serological assay for the detection of anti-SARS-CoV-2 antibodies; (ii) an amplification-free genetic assay for Pneumocystis pneumonia identification in respiratory specimens; and (iii) a novel approach to the early detection of lung cancer based on a biomarker panel combining protein and epigenetic analytes present in human plasma. The work in this thesis has opened the door to innovative analytical approaches for the diagnosis of lung-related disorders, overcoming some of the limitations of the conventional analytical techniques and exhibiting an enormous potential for their implementation in POC devices applicable in the real clinical practice