Functionalization and behavior in aqueous media of silicon surfaces for improved biochemical sensing

The silicon surface may be functionalized with organic groups through direct Si-C bonding, which provides the obtained surfaces with improved chemical stability and allows for the immobilization of probe molecules for the elaboration of sensors. We here review recent work done in our group, using carboxyl-terminated alkyl monolayers on model Si(111) surfaces as a benchmark to study in details further surface functionalization, then extending the processes to amorphous hydrogenated silicon and amorphous hydrogenated silicon/carbon alloys, which can be deposited in thin-film form on any substrate. By designing appropriate structures, fluorescence biochips were then obtained, with strongly improved performance in terms of sensitivity, stability and reliability.