Optical Biosensors for Label-Free Detection of Small Molecules

Label-free optical biosensors are an intriguing option for the analyses of many analytes, as they offer several advantages such as high sensitivity, direct and real-time measurement in addition to multiplexing capabilities. However, development of label-free optical biosensors for small molecules can be challenging as most of them are not naturally chromogenic or fluorescent, and in some cases, the sensor response is related to the size of the analyte. To overcome some of the limitations associated with the analysis of biologically, pharmacologically, or environmentally relevant compounds of low molecular weight, recent advances in the field have improved the detection of these analytes using outstanding methodology, instrumentation, recognition elements, or immobilization strategies. In this review, we aim to introduce some of the latest developments in the field of label-free optical biosensors with the focus on applications with novel innovations to overcome the challenges related to small molecule detection. Optical label-free methods with different transduction schemes, including evanescent wave and optical fiber sensors, surface plasmon resonance, surface-enhanced Raman spectroscopy, and interferometry, using various biorecognition elements, such as antibodies, aptamers, enzymes, and bioinspired molecularly imprinted polymers, are reviewed

Biosensing Based on Nanoparticles for Food Allergens Detection

Food allergy is one of the major health threats for sensitized individuals all over the world and, over the years, the food industry has made significant efforts and investments to offer safe foods for allergic consumers. The analysis of the concentration of food allergen residues in processing equipment, in raw materials or in the final product, provides analytical information that can be used for risk assessment as well as to ensure that food-allergic consumers get accurate and useful information to make their food choices and purchasing decisions. The development of biosensors based on nanomaterials for applications in food analysis is a challenging area of growing interest in the last years. Research in this field requires the combined efforts of experts in very different areas including food chemistry, biotechnology or materials science. However, the outcome of such collaboration can be of significant impact on the food industry as well as for consumer’s safety. These nanobiosensing devices allow the rapid, selective, sensitive, cost-effective and, in some cases, in-field, online and real-time detection of a wide range of compounds, even in complex matrices. Moreover, they can also enable the design of novel allergen detection strategies. Herein we review the main advances in the use of nanoparticles for the development of biosensors and bioassays for allergen detection, in food samples, over the past few years. Research in this area is still in its infancy in comparison, for instance, to the application of nanobiosensors for clinical analysis. However, it will be of interest for the development of new technologies that reduce the gap between laboratory research and industrial applications

Aluminum Nanoholes for Optical Biosensing

[EN] Sub-wavelength diameter holes in thin metal layers can exhibit remarkable optical features that make them highly suitable for (bio)sensing applications. Either as efficient light scattering centers for surface plasmon excitation or metal-clad optical waveguides, they are able to form strongly localized optical fields that can effectively interact with biomolecules and/or nanoparticles on the nanoscale. As the metal of choice, aluminum exhibits good optical and electrical properties, is easy to manufacture and process and, unlike gold and silver, its low cost makes it very promising for commercial applications. However, aluminum has been scarcely used for biosensing purposes due to corrosion and pitting issues. In this short review, we show our recent achievements on aluminum nanohole platforms for (bio)sensing. These include a method to circumvent aluminum degradation-which has been successfully applied to the demonstration of aluminum nanohole array (NHA) immunosensors based on both, glass and polycarbonate compact discs supports-the use of aluminum nanoholes operating as optical waveguides for synthesizing submicron-sized molecularly imprinted polymers by local photopolymerization, and a technique for fabricating transferable aluminum NHAs onto flexible pressure-sensitive adhesive tapes, which could facilitate the development of a wearable technology based on aluminum NHAs.The authors gratefully acknowledge financial support from MINECO projects, Spain (TEC2012-31145, CTQ2012-37573-C02 and CTQ 2013-45875-R).Angulo Barrios, C.; Canalejas Tejero, V.; Herranz, S.; Urraca, J.; Moreno-Bondi, MC.; Avella-Oliver, M.; Maquieira Catala, Á.... (2015). Aluminum Nanoholes for Optical Biosensing. Biosensors. 5(3):417-431. https://doi.org/10.3390/bios50304174174315

Comparative Study of the Performance of Two Different Luciferases for the Analysis of Fumonisin B1 in Wheat Samples

The development of two different immunoassays for the determination of fumonisin B1 in wheat samples is reported. A previously described mimopeptide for fumonisin B1 (FB1) was used to produce fusion proteins in combination with two different luciferases: Gaussia luciferase (GLuc) and NanoLuc luciferase (NLuc). The production, expression and the development of two immunoassays based on these fusion proteins (A2- GLuc and A2-NLuc) is detailed. The assay showing the best performance, A2-NLuc, with a limit of detection of 0.61 ngmL 1 and a dynamic range from 1.9 to 95 ngmL 1 , was employed for the analysis of spiked wheat samples, a reference matrix material, as well as naturally contaminated wheat samples. The recoveries obtained in the spiked samples were acceptable, between 81.5 and 109%, with relative standard deviations lower than 14%. The analysis of naturally contaminated wheat was validated by a liquid chromatography coupled to tandem mass detection method

"Chem-game", el juego como estrategia para la dinamización del aprendizaje y la evaluación de conocimientos en Química General

Este proyecto pretende aplicar la "gamificación" en la enseñanza de la asignatura de Química General de primer curso del grado en Química para fomentar la formación, creatividad, compromiso y la capacidad de trabajo en equipo de los estudiantes

Diseño y preparación de un laboratorio virtual de Química Analítica: Técnicas instrumentales de análisis

La reciente pandemia del COVID-19 ha supuesto un cambio excepcional y drástico de la concepción tradicional del aprendizaje, tanto para los estudiantes como para los docentes. Ante esta situación se requiere no sólo acciones que faciliten la adaptación de los estudiantes y profesores a las plataformas educativas en línea, sino también a que éstas se conviertan en auténticas herramientas para potenciar y mejorar de forma significativa el aprendizaje del alumno. El presente proyecto de Innovación Educativa y Mejora de la Calidad Docente pretende mejorar la calidad del aprendizaje de varias asignaturas de los Grados de Química e Ingeniería Química que llevan asociado un Laboratorio de Técnicas Instrumentales. Tradicionalmente esa docencia práctica ha sido presencial, pero la situación excepcional surgida con la pandemia en el curso 2019/2020, ha demostrado que disponer de unas prácticas virtualizadas es de gran ayuda para facilitar el aprendizaje de los alumnos y facilitar una transferencia del conocimiento constructivo y colaborativo. Desde hace años, el personal docente e investigador (PDI), personal de administración y servicios (PAS) y los estudiantes de la UCM, disponemos de la plataforma de enseñanza online Moodle (Campus Virtual, CV). Sin embargo, la pandemia que vivimos ha evidenciado la brecha digital en lo referente a cómo usar Moodle y, por ende, la utilización de las Tecnologías de Información y Comunicación (TICs) como facilitadoras didácticas. A pesar de nuestras limitaciones, tanto profesores como estudiantes, hemos desarrollado una enorme capacidad resiliente, lo que permitió, durante el pasado mes de mayo, la puesta en marcha de los primeros laboratorios en línea en el Departamento de Química Analítica de la UCM. Fruto de esta experiencia, así como de la situación actual de incertidumbre para el curso próximo, algunos profesores, estudiantes y PAS del departamento hemos decidido adelantarnos a un escenario futuro en el que se contemple nuevamente la impartición de Docencia Experimental en línea y solicitar el presente proyecto de Innovación Educativa y Mejora de la Calidad Docente

Female role models in analytical chemistry: then, now, and in the future

International audience“Who were your role models?” is a question we get asked seemingly at all relevant career stages of our scientific lives. Concerning women in chemistry, this question is often asked with more precision inquiring about our female role models in chemistry. This question is answered quickly—no need to think—because we have the fabulous, unparalleled in their historic successes, female chemists Marie and Irene Curie, and Rosalind Franklin, moving right along to Dorothy Hodgkin. All set! But, wait a moment, based on this superheroine foundation, we can dig deeper to answer this question with more specificity and actuality. Ada E. Yonath (2009) and Frances H. Arnold (2018), who were awarded Nobel Prizes in Chemistry for their outstanding scientific accomplishments, are more than obvious role models for so many of us. So let us keep going, because in addition we can identify with accuracy those important role models who did not inspire us from afar in history or afar from a Nobel worthy platform. Rather, they inspired us much more closely with their demonstrated ingenuity and creativity, persistence and success, and leadership accompanied with outstanding personalities. Here, choices become more personal, more focused on own fields of research, and are accompanied with the serendipity of having had a chance to meet these great women. We are talking about chemists of the caliber of Jacqueline K. Barton, Elizabeth (Lisa) A. H. Hall, Frances S. Ligler, Marja-Liisa Riekkola, Carol V. Robinson, and Dong Shaojun, to name a few of our truly outstanding female chemists who have served so many of us as role models scientifically‚ as well as personally‚ and whose excellence we aspire to emulate. Their excellence is underlined by having accomplished many “firsts” in their own universities and countries, by being recognized by their respective countries’ premier scientific academies, and by having contributed in major ways to their fields through seminal books and pioneering research