Nanoelectrode-based devices for electrical biodetection in liquid solution

Abstract

The fabrication of nanosystems for the electrical detection of biomolecular interactions is reported. Using a planar process on silicon involving high-resolution electron beam lithography and lift-off, we have demonstrated the reliable fabrication of nanoelectrode-based devices with controlled gap dimensions ranging from 100 nm down to 20 nm. These devices were used to achieve the electrical detection of gold colloids. We show that binding events can occur in inter-electrode gaps, leading to a drastic modification of the electrical transport through the nanojunction. Using a similar approach, electrical measurements in solution were performed by developing Poly(dimetylsiloxane) molded microtanks. First experiments involving gold colloids in solution have shown the possibility of detecting individual nanoparticles. The versatility and the very high sensitivity of these devices added to the simplicity of implementation make this approach very attractive for the fabrication of efficient nanobiosensors.