CP, T and CPT versus temporal asymmetries for entangled states of the B-d-system

The observables used in the K-system to characterize T and CPT violation are no longer useful for the Bd-system, since the width difference between the physical states is vanishingly small. We show that only Im(epsilon) and Re(delta) can survive if Delta Gamma=0, and build alternative CP-odd, CPT-odd, T-odd and temporal asymmetries for the (B_CP -> B0, B0bar) transitions. These quantities enable us to test T and CPT invariances of the effective Hamiltonian for the B-system. The method needs the CP eigenstates B_CP, which can be tagged unambiguously to order lambda^3 from the entangled states of a B-factory

Photo-click chemistry to create nucleic acids dextran-based microarrays

The final publication is available at link.springer.com[EN] In the literature, there are reports of the utilization of various hydrogels to create generic platforms for protein microarray applications. Here, a novel strategy was developed to obtain high-performance microarrays. In it, a dextran hydrogel is used to covalently immobilize oligonucleotides and proteins. This method employs aqueous solutions of dextran methacrylate (Dx-MA), which is a biocompatible photopolymerizable monomer. Capture probes are immobilized inside the hydrogel via a light-induced thiol-acrylate coupling reaction at the same time as the dextran polymer is formed. Hydrogel microarrays based on this technique were prepared on different surfaces, such as a Blu-ray Disk and polycarbonate or alkene-functionalized glass slides, and these systems showed high probe-loading capabilities and good biorecognition yields. This methodology presents advantages such as a low cost, a short analysis time, a low limit of detection, and multiplexing capabilities, among others. Confocal fluorescence microscopy analysis demonstrated that in these hydrogel-based microarrays, receptor immobilization and the biorecognition event occurred within the hydrogel and not merely on the surface.Funding from MINECO through the project BIHOLOG CTQ/2016/75749-R is acknowledged.Díaz-Betancor, Z.; Bañuls Polo, M.; Maquieira Catala, A. (2019). Photo-click chemistry to create nucleic acids dextran-based microarrays. Analytical and Bioanalytical Chemistry. 411(25):6745-6754. https://doi.org/10.1007/s00216-019-02050-3S6745675441125Heller MJ. DNA microarray technology: devices, systems, and applications. Annu Rev Biomed Eng. 2002;4:129–53. https://doi.org/10.1146/annurev.bioeng.4.020702.153438 .Sassolas A, Leca-Bouvier BD, Blum LJ. DNA biosensors and microarrays. Chem Rev. 2008;108:109–39. https://doi.org/10.1021/cr0684467 .Uttamchandani M, Neo JL, Ong BNZ, Moochhala S. Applications of microarrays in pathogen detection and biodefence. Trends Biotechnol. 2009;27:53–61. https://doi.org/10.1016/J.TIBTECH.2008.09.004 .Yu X, Schneiderhan-Marra N, Joos TO. Protein microarrays for personalized medicine. Clin Chem. 2010;56:376–87. https://doi.org/10.1373/clinchem.2009.137158 .North SH, Taitt CR. Immobilization of biomolecular probes for arrays and assay: critical aspects of biointerfaces. In: Chemoselective and bioorthogonal ligation reactions. Weinheim: Wiley-VCH; 2017. p. 459–95.Nimse S, Song K, Sonawane M, Sayyed D, Kim T. Immobilization techniques for microarray: challenges and applications. Sensors. 2014;14:22208–29. https://doi.org/10.3390/s141222208 .Cardenas-Benitez B, Djordjevic I, Hosseini S, Madou MJ, Martinez-Chapa SO. Review: Covalent functionalization of carbon nanomaterials for biosensor applications: an update. J Electrochem Soc. 2018;165:B103–17. https://doi.org/10.1149/2.0381803jes .Qu Z, Xu H, Gu H. Synthesis and biomedical applications of poly((meth)acrylic acid) brushes. ACS Appl Mater Interfaces. 2015;7:14537–51. https://doi.org/10.1021/acsami.5b02912 .Oh SJ, Hong BJ, Choi KY, Park JW. Surface modification for DNA and protein microarrays. OMICS. 2006;10:327–43. https://doi.org/10.1089/omi.2006.10.327 .Luderer F, Walschus U. Immobilization of oligonucleotides for biochemical sensing by self-assembled monolayers: thiol–organic bonding on gold and silanization on silica surfaces. In: Immobilisation of DNA on chips I. Berlin: Springer; 2005. p. 37–56.Caminade A-M. Dendrimers as biological sensors. In: Dendrimers. Chichester: Wiley; 2011. p. 375–92.Kiat NJ, Simeon F, Phon TH, Ajikumar PK. DNA-directed assembly microarray for protein and small molecule inhibitor screening. Totowa, NJ: Humana; 2011. p. 127–40.Basinska T. Reactions leading to controlled hydrophilicity/hydrophobicity of surfaces. Curr Org Chem. 2017;21(24):2479–501. https://doi.org/10.2174/1385272821666170428123013 .Weinrich D, Köhn M, Jonkheijm P, Westerlind U, Dehmelt L, Engelkamp H, et al. Preparation of biomolecule microstructures and microarrays by thiol-ene photoimmobilization. ChemBioChem. 2010;11:235–47. https://doi.org/10.1002/cbic.200900559 .Wendeln C, Rinnen S, Schulz C, Kaufmann T, Arlinghaus HF, Ravoo BJ. Rapid preparation of multifunctional surfaces for orthogonal ligation by microcontact chemistry. Chem Eur J. 2012;18:5880–8. https://doi.org/10.1002/chem.201103422 .Makaraviciute A, Ramanaviciene A. Site-directed antibody immobilization techniques for immunosensors. Biosens Bioelectron. 2013;50:460–71. https://doi.org/10.1016/j.bios.2013.06.060 .Bañuls M-J, Jiménez-Meneses P, Meyer A, Vasseur J-J, Morvan F, Escorihuela J, et al. Improved performance of DNA microarray multiplex hybridization using probes anchored at several points by thiol–ene or thiol–yne coupling chemistry. Bioconjug Chem. 2017;28:496–506. https://doi.org/10.1021/acs.bioconjchem.6b00624 .Neumann K, Conde-González A, Owens M, Venturato A, Zhang Y, Geng J, et al. An approach to the high-throughput fabrication of glycopolymer microarrays through thiol–ene chemistry. Macromolecules. 2017;50:6026–31. https://doi.org/10.1021/acs.macromol.7b00952 .Gupta N, Lin BF, Campos LM, Dimitriou MD, Hikita ST, Treat ND, et al. A versatile approach to high-throughput microarrays using thiol-ene chemistry. Nat Chem. 2010;2:138–45. https://doi.org/10.1038/nchem.478 .Rubina AY, Dementieva EI, Stomakhin AA, Darii EL, Pan’kov SV, Barsky VE, et al. Hydrogel-based protein microchips: manufacturing, properties, and applications. Biotechniques. 2003;34:1008–22. https://doi.org/10.2144/03345rr01 .Varshosaz J. Dextran conjugates in drug delivery. Expert Opin Drug Deliv. 2012;9:509–23. https://doi.org/10.1517/17425247.2012.673580 .Desmet C, Blum LJ, Marquette CA. High-throughput multiplexed competitive immunoassay for pollutants sensing in water. Anal Chem. 2012;84:10267–76. https://doi.org/10.1021/ac302133u .Moschallski M, Evers A, Brandstetter T, Rühe J. Sensitivity of microarray based immunoassays using surface-attached hydrogels. Anal Chim Acta. 2013;781:72–9. https://doi.org/10.1016/j.aca.2013.04.013 .Beyer A, Pollok S, Berg A, Weber K, Popp J. Easy daylight fabricated hydrogel Array for colorimetric DNA analysis. Macromol Biosci. 2014;14:889–98. https://doi.org/10.1002/mabi.201300487 .Alonso R, Jiménez-Meneses P, García-Rupérez J, Bañuls M-J, Maquieira Á. Thiol–ene click chemistry towards easy microarraying of half-antibodies. Chem Commun. 2018;54:6144–7. https://doi.org/10.1039/C8CC01369A .Escorihuela J, Bañuls MJ, Grijalvo S, Eritja R, Puchades R, Maquieira Á. Direct covalent attachment of DNA microarrays by rapid thiol-ene “click” chemistry. Bioconjug Chem. 2014;25:618–27.Escorihuela J, Bañuls M-J, Puchades R, Maquieira Á. Site-specific immobilization of DNA on silicon surfaces by using the thiol–yne reaction. J Mater Chem B. 2014;2:8510–7. https://doi.org/10.1039/C4TB01108B .Escorihuela J, Bañuls MJ, Puchades R, Maquieira Á. Development of oligonucleotide microarrays onto Si-based surfaces via thioether linkage mediated by UV irradiation. Bioconjug Chem. 2012;23:2121–8.Dondoni A. The emergence of thiol–ene coupling as a click process for materials and bioorganic chemistry. Angew Chem Int Ed. 2008;47:8995–7. https://doi.org/10.1002/anie.200802516 .Mira D, Llorente R, Morais S, Puchades R, Maquieira A, Marti J. High-throughput screening of surface-enhanced fluorescence on industrial standard digital recording media. Proc SPIE. 2004;5617:364–73.van Dijk-Wolthuis WNE, Franssen O, Talsma H, van Steenbergen MJ, Kettenes-van den Bosch JJ, Hennink WE. Synthesis, characterization, and polymerization of glycidyl methacrylate derivatized dextran. Macromolecules. 1995;28:6317–22. https://doi.org/10.1021/ma00122a044 .Pirrung MC. How to make a DNA chip. Angew Chem Int Ed. 2002;41:1276–89. https://doi.org/10.1002/1521-3773(20020415)41:83.0.CO;2-2 .Wang C, Jia X-M, Jiang C, Zhuang G-N, Yan Q, Xiao S-J. DNA microarray fabricated on poly(acrylic acid) brushes-coated porous silicon by in situ rolling circle amplification. Analyst. 2012;137:4539. https://doi.org/10.1039/c2an35417a .Casanova-Salas I, Rubio-Briones J, Calatrava A, Mancarella C, Masiá E, Casanova J, et al. Identification of miR-187 and miR-182 as biomarkers of early diagnosis and prognosis in patients with prostate cancer treated with radical prostatectomy. J Urol. 2014;192:252–9. https://doi.org/10.1016/j.juro.2014.01.107

Holographic Recording of Unslanted Volume Transmission Gratings in Acrylamide/Propargyl Acrylate Hydrogel Layers: Towards Nucleic Acids Biosensing

[EN] The role of volume hydrogel holographic gratings as optical transducers in sensor devices for point-of-care applications is increasing due to their ability to be functionalized for achieving enhanced selectivity. The first step in the development of these transducers is the optimization of the holographic recording process. The optimization aims at achieving gratings with reproducible diffraction efficiency, which remains stable after reiterative washings, typically required when working with analytes of a biological nature or several step tests. The recording process of volume phase transmission gratings within Acrylamide/Propargyl Acrylate hydrogel layers reported in this work was successfully performed, and the obtained diffraction gratings were optically characterized. Unslanted volume transmission gratings were recorded in the hydrogel layers diffraction efficiencies; up to 80% were achieved. Additionally, the recorded gratings demonstrated stability in water after multiple washing steps. The hydrogels, after functionalization with oligonucleotide probes, yields a specific hybridization response, recognizing the complementary strand as demonstrated by fluorescence. Analyte-sensitive hydrogel layers with holographic structures are a promising candidate for the next generation of in vitro diagnostic tests.This work was financially supported by the E.U. FEDER, the Spanish Ministry of Science and Innovation (ADBIHOL-PID2019-110713RB-I00/AEI/10.13039/501100011033) and Generalitat Valenciana (PROMETEO/2020/094). M. I. Lucio acknowledges MINECO for her Juan de la Cierva-Incorporacion grants (IJC 2018-035355-I). P. Zezza acknowledges the Generalitat Valenciana for her S. Grisolia grant and the UPV for the mobility grant (BEFPI 2022). Funding was also received from Aid for First Research Projects (PAID-06-22) and the Vice-rectorate for Research of the Universitat Politecnica de Valencia (UPV). Partially funded by the European Space Agency, through PEA4000129503 collaborative project: Wound Healing In Space: Key challenges towards Intelligent and Enabling Sensing platforms.Zezza, P.; Lucío, MI.; Naydenova, I.; Bañuls Polo, M.; Maquieira Catala, A. (2023). Holographic Recording of Unslanted Volume Transmission Gratings in Acrylamide/Propargyl Acrylate Hydrogel Layers: Towards Nucleic Acids Biosensing. Gels. 9(9). https://doi.org/10.3390/gels90907109

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

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

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

Surface Micro-Patterned Biofunctionalized Hydrogel for Direct Nucleic Acid Hybridization Detection

[EN] The present research is focused on the development of a biofunctionalized hydrogel with a surface diffractive micropattern as a label-free biosensing platform. The biosensors described in this paper were fabricated with a holographic recording of polyethylene terephthalate (PET) surface micro-structures, which were then transferred into a hydrogel material. Acrylamide-based hydrogels were obtained with free radical polymerization, and propargyl acrylate was added as a comonomer, which allowed for covalent immobilization of thiolated oligonucleotide probes into the hydrogel network, via thiol-yne photoclick chemistry. The comonomer was shown to significantly contribute to the immobilization of the probes based on fluorescence imaging. Two different immobilization approaches were demonstrated: during or after hydrogel synthesis. The second approach showed better loading capacity of the bioreceptor groups. Diffraction efficiency measurements of hydrogel gratings at 532 nm showed a selective response reaching a limit of detection in the complementary DNA strand of 2.47 mu M. The label-free biosensor as designed could significantly contribute to direct and accurate analysis in medical diagnosis as it is cheap, easy to fabricate, and works without the need for further reagents.This work was financially supported by the E.U. FEDER, the Spanish Ministry of Science and Innovation (ADBIHOL-PID2019-110713RB-I00/AEI/10.13039/501100011033) and Generalitat Valenciana (PROMETEO/2020/094). M. I. Lucío acknowledges her Juan de la Cierva-Incorporación grant (IJC 2018-035355-I) funded by MCIN/AEI/10.13039/501100011033. P. Zezza acknowledges Generalitat Valenciana for her Grisolia fellowship grant.Zezza, P.; Lucío, MI.; Fernández, E.; Maquieira Catala, A.; Bañuls Polo, M. (2023). Surface Micro-Patterned Biofunctionalized Hydrogel for Direct Nucleic Acid Hybridization Detection. Biosensors. 13(3). https://doi.org/10.3390/bios1303031213

Covalent attachment of biotinylated molecular beacons via thiol-ene coupling. A study on conformational changes upon hybridization and streptavidin binding

[EN] The authors describe a method for the detection of DNA by using immobilized molecular beacons (MBs) on the surface of silicon, with a view on possible application in biosensing. MB hybridization and protein recognition were interrogated on silicon-oninsulator (SOI) surfaces by using fluorescently tagged probes. In order to better understand the conformational changes that occur to MBs upon hybridization, the process was studied by using dual polarization interferometry (DPI). A model system was developed that matches thickness, mass, and density parameters. The results experimentally demonstrate that hybridization promotes the displacement of a protein away from the surface. This finding may be further exploited in techniques such as photonic sensors, thereby paving the way to the design of more sensitive biosensors based on the use of MBs.This research was funded by the European Union Horizon 2020 program (ICT-644242 SAPHELY project), the MINECO projects CTQ/2013/45875-R, and CTQ/2016/75749-R, FEDER, and GVA PROMETEO II 2014/40.Gonzalez-Lucas, D.; Bañuls Polo, M.; García-Rupérez, J.; Maquieira Catala, Á. (2017). Covalent attachment of biotinylated molecular beacons via thiol-ene coupling. A study on conformational changes upon hybridization and streptavidin binding. Microchimica Acta. 184(9):3231-3238. https://doi.org/10.1007/s00604-017-2310-4S323132381849Huertas CS, Fariña D, Lechuga LM (2016) Direct and label-free quantification of micro-RNA-181a at Attomolar level in complex media using a Nanophotonic biosensor. ACS Sensors 1(6):748–756Bañuls M-J, González-Pedro V, Barrios CA, Puchades R, Maquieira Á (2010) Selective chemical modification of silicon nitride/silicon oxide nanostructures to develop label-free biosensors. Biosens Bioelectron 25(6):1460–1466Zhang G-J, Chua JH, Chee R-E, Agarwal A, Wong SM (2009) Label-free direct detection of MiRNAs with silicon nanowire biosensors. Biosens Bioelectron 24(8):2504–2508Sassolas A, Leca-Bouvier BD, Blum LJ (2008) DNA biosensors and microarrays. Chem Rev 108(1):109–139Chen T, Tan W (2013) Molecular beacons on solid surfaces. In: Yang CJ, Tan W (eds) Molecular Beacons. Springer, Berlin Heidelberg, pp 75–90Wang K, Tang Z, Yang CJ, Kim Y, Fang X, Li W, Wu Y, Medley CD, Cao Z, Li J, Colon P, Lin H, Tan W (2009) Molecular engineering of DNA: molecular beacons. Angew Chem Int Ed 48(5):856–870Zheng J, Yang R, Shi M, Wu C, Fang X, Li Y, Li J, Tan W (2015) Rationally designed molecular beacons for bioanalytical and biomedical applications. Chem Soc Rev 44(10):3036–3055Guo Q, Bai Z, Liu Y, Sun Q (2016) A molecular beacon microarray based on a quantum dot label for detecting single nucleotide polymorphisms. Biosens Bioelectron 77:107–110Mei Z, Tang L (2016) Surface plasmon coupled fluorescence enhancement based on ordered gold nanorod array biochip for ultra-sensitive DNA analysis. Anal Chem 89(1):633–639Li S, Wang Y, Gao C, Ge S, Yu J, Yan M (2015) “Signal-off” photoelectrochemical DNA sensing strategy based on target dependent DNA probe conformational conversion using CdS quantum dots sensitized TiO2 nanorods array as photoactive material. J Electroanal Chem 759:38–45Escorihuela J, Bañuls M-J, Grijalvo S, Eritja R, Puchades R, Maquieira Á (2014) Direct covalent attachment of DNA microarrays by rapid thiol–Ene “click” chemistry. Bioconjug Chem 25(3):618–627Yao G, Tan W (2004) Molecular-beacon-based array for sensitive DNA analysis. Anal Biochem 331(2):216–223Du H, Strohsahl CM, Camera J, Miller BL, Krauss TD (2005) Sensitivity and specificity of metal surface-immobilized “molecular beacon” biosensors. J Am Chem Soc 127(21):7932–7940Escorihuela J, Banuls MJ, Puchades R, Maquieira A (2012) DNA microarrays on silicon surfaces through thiol-ene chemistry. Chem Commun 48(15):2116–2118Zhao W-W, Wang J, Xu J-J, Chen H-Y (2011) Energy transfer between CdS quantum dots and au nanoparticles in photoelectrochemical detection. Chem Commun 47(39):10990–10992Bayer EA, Wilchek M (1990) Biotin-binding proteins: overview and prospects. In: Meir W, Edward AB (eds) Methods in enzymology, vol 184. pp 49–51Escorihuela J, González-Martínez MÁ, López-Paz JL, Puchades R, Maquieira Á, Gimenez-Romero D (2015) Dual-polarization interferometry: a novel technique to light up the nanomolecular world. Chem Rev 115(1):265–294Mira D, Llorente R, Morais S, Puchades R, Maquieira A, Marti J (2004) High-throughput screening of surface-enhanced fluorescence on industrial standard digital recording media. In: Proc. SPIE, pp 364–373Volcke C, Gandhiraman RP, Gubala V, Doyle C, Fonder G, Thiry PA, Cafolla AA, James B, Williams DE (2010) Plasma functionalization of AFM tips for measurement of chemical interactions. J Colloid Interface Sci 348(2):322–328Georgiadis R, Peterlinz KP, Peterson AW (2000) Quantitative measurements and modeling of kinetics in nucleic acid monolayer films using SPR spectroscopy. J Am Chem Soc 122(13):3166–3173Elhadj S, Singh G, Saraf RF (2004) Optical properties of an immobilized DNA monolayer from 255 to 700 nm. Langmuir 20(13):5539–5543Xu K, Ouberai MM, Welland ME (2013) A comprehensive study of lysozyme adsorption using dual polarization interferometry and quartz crystal microbalance with dissipation. Biomaterials 34(5):1461–1470Cowsill BJ, Coffey PD, Yaseen M, Waigh TA, Freeman NJ, Lu JR (2011) Measurement of the thickness of ultra-thin adsorbed globular protein layers with dual-polarisation interferometry: a comparison with neutron reflectivity. Soft Matter 7(16):7223–723

Evaluación on-line de la competencia “instrumental específica”

[EN] The capacity to use updated techniques necessary for the professional practice is an essential skill to be acquired by any college student. To ensure that acquisition, the higher education system must supply itself with appropriate assessment tools. In this study, an online test based on elearning platform PoliformaT (Sakai technology) is proposed to assess learning outcomes "specific instrumental" competency in degrees that include training in chemistry. The test consists of multiple-response questions randomly selected of a battery. The questions are designed to assess different aspects of technologies and instruments of the profession, such as background, elements, technical problems and application. The evaluation has been tested in two subjects of the Degree of Biotechnology (98 students) and the Degree of Science and Food Technology (76 students). We have analysed the percentages of successes achieved studying the influence of the degree and type of question. The results show that students acquire the expected skills and the evaluation system has been successfully accepted. The collected evidences provide information for future improvements and the way to extend the innovation to other areas.[ES] La capacidad para utilizar las técnicas actualizadas necesarias para la práctica de la profesión es una competencia esencial que debe adquirir cualquier estudiante universitario. Para garantizar dicha adquisición, el sistema educativo superior debe dotarse de herramientas evaluativas apropiadas. En este estudio, se propone una prueba on-line basada en la plataforma de e-learning PoliformaT (tecnología Sakai) para evaluar los resultados de aprendizaje de la competencia “instrumental específica” en titulaciones que incluyan formación en química. La prueba consiste en cuestiones de respuesta múltiple seleccionadas aleatoriamente de una batería. Dichas cuestiones han sido diseñadas para evaluar diferentes aspectos de las tecnologías e instrumentos propios de la profesión, tales como fundamentos, elementos, problemas técnicos y su aplicación. La evaluación ha sido probada en dos asignaturas del Grado en Biotecnología (98 alumnos) y del Grado en Ciencia y Tecnología de Alimentos (76 alumnos). Se han analizado los porcentajes de aciertos alcanzados estudiando la influencia del Grado y el tipo de pregunta. Los resultados obtenidos demuestran que los alumnos adquieren la competencia y que el sistema de evaluación ha sido aceptado satisfactoriamente. Las evidencias recogidas proporcionan información para futuras mejoras y el modo de extender la innovación a otros ámbitos.Tortajada Genaro, LA.; Bañuls Polo, MJ.; Maquieira Catala, Á. (2016). Evaluación on-line de la competencia “instrumental específica”. En In-Red 2016. II Congreso nacional de innovación educativa y docencia en red. Editorial Universitat Politècnica de València. https://doi.org/10.4995/INRED2016.2016.4313OC

Thiol-click photochemistry for surface functionalization applied to optical biosensing

[EN] In the field of biosensing, suitable procedures for efficient probes immobilization are of outmost importance. Here we present different light-based strategies to promote the covalent attachment of thiolated capture probes (oligonucleotides and proteins) on different materials and working formats. One strategy employs epoxylated surfaces and uses the light to accomplish the ring opening by a thiol moiety present in a probe. However, most of this work lies on the use of thiol-ene photocoupling chemistry to covalently attach probes to the supports. And thus, both alkenyl and thiol derivatized surfaces are assayed to immobilize thiol or alkene ended probes, respectively, and their performances are compared. Also, the effect of the number of thiols carried by the probe is analyzed comparing single-point and multi-point attachment. The performance of the analogous tethering, but onto alkynylated surfaces is also carried out, and the sensing response is related to the surfaces hydrophobicity. A newly developed reaction is also discussed where a fluorinated surface undergoes the covalent immobilization of thiolated probes activated by light, creating small hydrophilic areas where the probes are attached, and leaving the rest of the surface highly hydrophobic and repellent against protein unspecific adsorption. These mixed surfaces confine the sample (aqueous) uniquely on the hydrophilic spots lowering the background signal and thus increasing the sensitivity. These probe immobilization approaches are applied to fluorescence microarray and label-free nanophotonic biosensing. All the exposed reactions have in common the photoactivation of the thiol moieties, and give rise to quick, clean, versatile, orthogonal and biocompatible reactions. Water is the only solvent used, and light the only catalyzer applied. Thus, all of them can be considered as having the attributes of click-chemistry reactions. For these reasons we named them as thiol-click photochemistry, being a very interesting pool of possibilities when building a biosensor.This work was supported by the European Union program Horizon 2020, projects H2020-PHC-634013 and H2020-ICT-644242, and by the Spanish Ministry of Economy and Competitiveness, project CTQ2016-75749-R. Authors thank the whole "Signal and Measurement" research group, from the IDM, UPV, for sharing space, research and life. Special thanks to Pilar Jimenez-Meneses, Rafael Alonso, Daniel Gonzalez-Lucas, Pilar Aragon and Patricia Noguera for their contribution to the development of thiol photoattaching chemistry and surface wettability modulation.Bañuls Polo, M.; González Martínez, MÁ.; Sabek, J.; García-Rupérez, J.; Maquieira Catala, Á. (2019). Thiol-click photochemistry for surface functionalization applied to optical biosensing. Analytica Chimica Acta. 1060:103-113. https://doi.org/10.1016/j.aca.2019.01.055S103113106