Modulating receptor-ligand binding in biorecognition by setting surface wettability

[EN] Modulation of support wettability used for microarray format biosensing has led to an improvement of results. Hydrophobicity of glass chips was set by derivatizing with single vinyl organosilanes of different chain length and silane mixtures. Thiol-ene photochemical linking has been used as effective chemistry for covalent anchoring of thiolated probes. Lowest unspecific binding and highest signal intensity and SNR were obtained with large hydrocarbon chain (C-22) silanes or a shorter one (C-10) containing fluorine atoms. SNR resulting values are improved, reaching levels higher than 1500 in some cases, when using vinyl silanes modified with 1% C-10 alkyl fluorinated one, because mild hydrophobicity was achieved (water contact angle ca. 110 degrees) for all silanes, including the short C-2 and C-3, thus giving rise to smaller and better defined array spots. In addition, unspecific binding of reagents and targets was totally withdrawn. Hence, good-performing surfaces for biosensing applications can be built using appropriate organosilane reagent selection, including fluorinated ones. We thank Patricia Concepcion and Dolores Soriano (Instituto de Tecnologia Quimica, Universitat Politecnica de Valencia-Consejo Superior de Investigaciones Cientificas) for helping with XPS analysis. Financial support from the Generalitat Valenciana (GVA-PROMETEO/2014/040), FEDER, and the Spanish Ministry of Economy and Competitiveness (CTQ2013-45875-R and CTQ2016-75749-R) is acknowledged. Aragón Revuelta, P.; Noguera Murray, PS.; Bañuls Polo, M.; Puchades, R.; Maquieira Catala, A.; González Martínez, MÁ. (2018). Modulating receptor-ligand binding in biorecognition by setting surface wettability. Analytical and Bioanalytical Chemistry. 410(23):5723-5730. https://doi.org/10.1007/s00216-018-1247-8 González-Martínez MA, Puchades R, Maquieira A. Optical immunosensors for environmental monitoring: how far have we come? Anal Bioanal Chem. 2007;387:205–18. Kontogeorgis GM, Kiil S. Intermolecular and interparticle forces. In: Kontogeorgis GM, Kiil S, editors. Introduction to applied colloid and surface chemistry. Chichester: Wiley; 2016. p. 11–33. Ronkainen NJ, Halsall HB, Heineman WR. Electrochemical immunoassays and immunosensors. In: van Emon JM, editor. Immunoassay and other bioanalytical methods. Boca Raton: CRC Press, Taylor & Francis Group; 2007. Chapter 16. González-Lucas D, Bañuls M-J, Puchades R, Maquieira A. Versatile and easy fabrication of advanced surfaces for high pe