Novel DNA Biosensor Based on the Out-of-Equilibrium Body Potential Method in Silicon-on-Insulator

In this paper, we applied the out-of-equilibrium body potential measurements in a silicon-on-insulator (SOI) structure as a mean of DNA detection. The biochips were manufactured by 3-glycidoxypropyltrimethoxysilane (GOPTMS) functionalization, and single stranded DNA probes corresponding to human papillomavirus (HPV) were grafted onto the surface. The physicochemical characteristics were assessed by contact angle, Fourier Transform Infrared Spectrometry (FTIR) and microarray technique. The effects of the bio-chemical attachments to the surface of SOI were evaluated by body potential measurements implemented in the Ψ-MOSFET configuration, typically used for electrical characterization of substrates. Body potential measurements versus the back gate voltage were able to distinguish the shift induced by DNA molecules only and the signatures were related to target DNA concentrations. The proposed reading method is remarkable owing to the fact that (1) it measures a potential (in the order of 1V) instead of a low current, (2) it allows fast sweeping measurements and (3) it requires a gate voltage close to 0V which induces less stress on the molecules attached to the surface.