Fluor-thiol Photocoupling Reaction for Developing High Performance Nucleic Acid (NA) Microarrays

Spatially controlled anchoring of NA probes onto microscope glass slides by a novel fluor-thiol coupling reaction is performed. By this UV-initiated reaction, covalent immobilization in very short times (30 s at 254 nm) is achieved with probe densities of up to 39.6 pmol/cm2. Modulating the surface hydrophobicity by combining a hydrophobic silane and a hydrophilic silane allows the fabrication of tuned surfaces where the analyte approaches only the anchored probe, which notably reduces nonspecific adsorption and the background. The generated substrates have proven clear advantages for discriminating single-base-pair mismatches, and for detecting bacterial PCR products. The hybridization sensitivity achieved by these high-performance surfaces is about 1.7 pM. Finally, this anchoring reaction is demonstrated using two additional surfaces: polytetrafluoroethylene (PTFE) and polyvinylidene fluoride (PVDF) membranes. This provides a very interesting pathway for anchoring thiolated biomolecules onto surfaces with C–F motifs via a quick clean UV reaction.Financial support from INTERBOINTER (project CTQ2013-45875-R) and BIHOLOG (Project CTQ2016-75749-R), FEDER, and GVA PROMETEO II 2014/040 is acknowledged. P.J.-M. acknowledges the Spanish Ministry of Economy, Industry and Competitiveness for the public FPI grant (Project CTQ2013-45875-R) and the cofinancing by the European Social Fund

Chemical Surface Modifications development of Silicon Based Label Free Integrated Optical (IO) Biosensors: A Review

[EN] Increasing interest has been paid to label-free biosensors in recent years. 11 Among them, refractive index (RI) optical biosensors enable high density and the chip-12 scale integration of optical components. This makes them more appealing to help 13 develop lab-on-a-chip devices. Today, many RI integrated optical (IO) devices are made 14 using silicon-based materials. A key issue in their development is the 15 biofunctionalization of sensing surfaces because they provide a specific, sensitive 16 response to the analyte of interest. This review critically discusses the 17 biofunctionalization procedures, assay formats and characterization techniques 18 employed in setting up IO biosensors. In addition, it provides the most relevant results 19 obtained from using these devices for real sample biosensing. Finally, an overview of 20 the most promising future developments in the fields of chemical surface modification 21 and capture agent attachment for IO biosensors follows.This research has been supported by the Spanish Ministry of Science and Innovation through project CTQ2010-15943/BQU and by the Regional Valencian Government, through GVA/PROMETEO 2010/08. The authors thank Dr. Miguel Holgado, from the Universidad Politecnica de Madrid, for his helpful discussion about the classification of RI optical sensors.Bañuls Polo, MJ.; Puchades Pla, R.; Maquieira Catala, Á. (2013). Chemical Surface Modifications development of Silicon Based Label Free Integrated Optical (IO) Biosensors: A Review. Analytica Chimica Acta. 777:1-16. https://doi.org/10.1016/j.aca.2013.01.025S11677

Novel and rapid activation of polyvinylidene fluoride membranes by UV light

[EN] Polyvinylidene fluoride (PVDF) membranes have become essential because of their huge applicability to the industry; however, they still present some limitations. This study focuses on the modification of PVDF membrane properties such as hydrophobicity, wettability, and functionality. To obtain a stable grafting, the surface of the membrane is hydroxylated using UV light at 254¿nm, followed by covalent immobilization of (3-aminopropyl)triethoxysilane (APTES) and vinyltriethoxysilane (VTES). The physicochemical and morphological properties of modified and raw PVDF membranes were analyzed by spectroscopy, microscopy, and goniometry. Finally, nucleic acid microarray technology results showed that PVDF and PVDF-VTES membranes had probe immobilization densities of 5 and 11¿pmol/cm2 and hybridization limits of detection of 1 and 5¿nM, respectively.Financial support from Spanish Ministry of Economy and Competitiveness (BIHOLOG Project CTQ2016-75749-R) and FEDER is acknowledged. P.J.-M. acknowledges the Spanish Ministry of Economy, Industry and Competitiveness for the public FPI grant (Project CTQ2013-45875-R) and cofinancing by the European Social Fund.Jimenez-Meneses, P.; Bañuls Polo, M.; Puchades, R.; Maquieira Catala, A. (2019). Novel and rapid activation of polyvinylidene fluoride membranes by UV light. Reactive and Functional Polymers. 140:56-61. https://doi.org/10.1016/j.reactfunctpolym.2019.04.012S566114

Fluor-thiol Photocoupling Reaction for Developing High Performance Nucleic Acid (NA) Microarrays

[EN] Spatially controlled anchoring of NA probes onto microscope glass slides by a novel fluor-thiol coupling reaction is performed. By this UV-initiated reaction, covalent immobilization in very short times (30 s at 254 nm) is achieved with probe densities of up to 39.6 pmol/cm(2). Modulating the surface hydrophobicity by combining a hydrophobic silane and a hydrophilic silane allows the fabrication of tuned surfaces where the analyte approaches only the anchored probe, which notably reduces nonspecific adsorption and the background. The generated substrates have proven clear advantages for discriminating single-base-pair mismatches, and for detecting bacterial PCR products. The hybridization sensitivity achieved by these high-performance surfaces is about 1.7 pM. Finally, this anchoring reaction is demonstrated using two additional surfaces: polytetrafluoroethylene (PTFE) and polyvinylidene fluoride (PVDF) membranes. This provides a very interesting pathway for anchoring thiolated biomolecules onto surfaces with C-F motifs via a quick clean UV reaction.Financial support from INTERBOINTER (project CTQ2013-45875-R) and BIHOLOG (Project CTQ2016-75749-R), FEDER, and GVA PROMETEO II 2014/040 is acknowledged. The authors also thank Dr. Tortajada-Genaro and Dr. Ninoles Rodenes for providing the Salmonella and Campylobacter PCR-amplified products. P.J.-M. acknowledges the Spanish Ministry of Economy, Industry and Competitiveness for the public FPI grant (Project CTQ2013-45875-R) and the cofinancing by, the European Social Fund. Dr. Miguel Angel Gonzalez-Martinez, Dr. Sergio Navalon, and Dr. Patricia Concepcion from Universitat Politecnica de Valencia are acknowledged for their help in the XPS analysis.Jimenez-Meneses, P.; Bañuls Polo, M.; Puchades, R.; Maquieira Catala, A. (2018). Fluor-thiol Photocoupling Reaction for Developing High Performance Nucleic Acid (NA) Microarrays. Analytical Chemistry. 90(19):11224-11231. https://doi.org/10.1021/acs.analchem.8b00265S1122411231901

Site-specific immobilization of DNA on silicon surfaces by using the thiol-yne reaction

[EN] Covalent immobilization of ssDNA fragments onto silicon-based materials was performed using the thiol-yne reaction. Chemical functionalization provided alkyne groups on the surface where the thiol-modified oligonucleotide probes can be easily photoattached as microarrays, reaching an immobilization density around 30 pmol cm(-2). The developed method presents the advantages of spatially controlled probe anchoring (by using a photomask), direct attachment without using cross-linkers, and short irradiation times (20 min). Hybridization efficiencies up to 70%, with full complementary strands, were reached. The approach was evaluated by scoring single nucleotide polymorphisms with a discrimination ratio around 15. Moreover, the potential applicability of the proposed methodology is demonstrated through the specific detection of 20 nM of a genomic target of bacterial Escherichia coli.This research was supported by Ministerio de Ciencia e Innovacion (CTQ2013-45875-R) and Generalitat Valenciana (PROMETEO/2010/008).Escorihuela Fuentes, J.; Bañuls Polo, M.; Puchades, R.; Maquieira Catala, Á. (2014). Site-specific immobilization of DNA on silicon surfaces by using the thiol-yne reaction. Journal of Materials Chemistry B. 2(48):8510-8517. https://doi.org/10.1039/c4tb01108bS8510851724

Biosensado con redes de nanoagujeros en oxido de aluminio

Se presenta la explotación analítica de redes de nanoagujeros de óxido de aluminio fabricados sobre sustratos de policarbonato.1 Este novedoso dispositivo se basa en la resonancia de plasmón superficial para monitorizar procesos de bioreconocimiento sin marcaje. El bajo coste de los materiales empleados (policarbonato y aluminio) y la compatibilidad de este dispositivo con las tecnologías de disco compacto encierra un gran potencial para el desarrollo de biosensores

Diferencias individuales y riesgo en la conducción. Historia de un reto todavía no resuelto

Se puede hablar con total propiedad de una tradición española en el estudio y la aplicación de los conocimientos psicológicos al fenómeno del tráfico, que se inicia en los años 20, si bien los primeros trabajos sistemáticos se realizaron fuera de nuestras fronteras. Se trata probablemente de la única competencia profesional de intervención psicológica regulada legalmente y mantenida a lo largo de toda la historia contemporánea española. El hilo conductor lo ha constituido el examen psicotécnico de selección de conductores -a profesionales primero, y a todos los conductores después- que en su estructura revela la evolución de la psicología. Con todo, paulatinamente se ha ido produciendo una ampliación, diversificación y complicación del interés científico y tecnológico por este ámbito clave del comportamiento humano, pasándose de una psicotecnia subjetiva hacia otra objetiva, y finalmente con un modelo evalutativo-interventivo hacia una psicología general aplicada a la problemática de la seguridad vial

Efectos psicológicos de la exposición al tráfico en conductores profesionales y noveles

Este trabajo ofrece una aproximación empírica a la problemática de la variable emocional ansiedad en una muestra de conductores profesionales y noveles. Esta reacción emocional está presente en un elevado número de sujetos accidentados, además de ser una de las emociones que más aducen las personas cuando conducen. La investigación se acerca al estudio de la propia situación de tráfico como generadora de ansiedad, variable medida a través del Inventario de Situaciones Ansiógenas del Tráfico (ISAT, Bañuls, 1993). Nuestro objetivo se centra en determinar si realmente la exposición al tráfico, mayor obviamente en los conductores profesionales, genera mayores niveles de ansiedad en estos, en comparación con los conductores noveles, así como mostrar qué situaciones potencialmente generadoras de ansiedad se relacionan con accidentalidad en ambas muestran de conductores. Los conductores noveles puntúan significativamente más al-to que los conductores profesionales en aquellas situaciones denominadas de evaluación externa y aquellas que impedimentos externos y retenciones, mientras que, los profesionales destacan en aquellas situaciones que denotan autoevaluación del sujeto y aquellas que implican críticas y agresión provenientes de los conductores de otros vehículos.This work offers an empirical approximation to the problems of the emotional variable anxiety in a professional drivers sample and novice. This emotional reaction is present in a high number of injured subjects, in addition to be other of the emotions that more cite the persons when drive. The investigation tries the study of the own traffic situation as generating of anxiety, measure through Inventario de Situaciones Ansiógenas en el Tráfico (ISAT, Bañuls, 1993). Our objective is centered in determining if actually the exposition to the traffic, greater obviously in the professional drivers, generates greater anxiety levels in these, in comparison with the conductors novice, as well as to show what potentially generating situations of anxiety are related to the accident rates in both samples of drivers. The novice drivers punctuate significantly higher than the professional drivers in those designated situations of external evaluation and those than external impediments and withholdings, while, the professionals underline in those situations that denote self-evaluation of the subject and those that imply critical and aggression originating from the drivers of other vehicles.Psicologí