Towards a microfluidic nucleic acid biosensor: Use of photochemistry for immobilization of a density gradient of probes.

摘要

A class of photolabile protecting groups, namely nitrobenzyl derivatives were investigated for the purpose of finding a suitable reactive coupling group to be used in the manufacture of slides for the development of a microfluidic nucleic acid biosensor. The ideal photolabile protecting group would enable quantitative control of the covalent immobilization chemistry used for attachment of nucleic acid probes on the biosensor surface. Nitrobenzyl bromide, a nitrobenzyl-ether olefin siloxane and a nitrobenzyl-ester olefin siloxane were the systems of study. While the three systems all could provide for covalent coupling, none provided sufficient control to permit practical and reproducible applications in the development of the biosensor. With respect to the nitrobenzyl bromide system, the stoichometry could not be controlled and the extreme water sensitivity was a problem. The ether and ester systems required excessive deprotection reaction time, even when exposed to intense UV radiation and did not exhibit sufficient reproducibility.