Gold nanoparticles detection using intrinsic SOI-based sensor

Ultra-thin Silicon-on-Insulator films, in the pseudo-MOSFET configuration, have been used to detect the presence of charged gold nanoparticles on their top free surface. The detection is based on the coupling between the free surface and the channel created at the silicon film - buried oxide interface. The presence of the charged particles on the free surface induces shifts in the electrical characteristics of the channel. The specific response to gold particles was identified by functionalization of the surface, before adding the particles. Reproducibility issues are discussed. An increase of the detection sensitivity with the use of ultra-thin films is obtained. These results open a path towards very simple, technology-light bio-chemical sensors.