Modulating receptor-ligand binding in biorecognition by setting surface wettability.

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 (C22) silanes or a shorter one (C10) containing fluorine atoms. SNR resulting values are improved, reaching levels higher than 1500 in some cases, when using vinyl silanes modified with 1% C10 alkyl fluorinated one, because mild hydrophobicity was achieved (water contact angle ca. 110°) for all silanes, including the short C2 and C3, 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 In addition, unspecific binding of reagents and targets was totally withdrawn.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. Graphical abstract ᅟ.