Electrical Transport and Chemical Sensing Properties of Gold Nanowires

Metal nanowires draw large attention due to their wide application, such as in electronic and sensor devices. In this study, we explored the electrical and chemical-sensing behaviors of gold nanowires fabricated by Focused Ion Beam etching (FIB) and Electron Beam Lithography (EBL). The chemical sensor is composed of a single nanowire connected to two gold contact pads. The resistivity of nanowires fabricated by EBL shows a size effect that thinner nanowires have higher resistivity. Nanowires fabricated by FIB etching show greatly reduced sensitivity toward molecular adsorption compared to those fabricated by EBL, though nanowires fabricated by FIB etching exhibit very high resistivity. Gold nanowires fabricated by EBL show different chemical sensing behavior upon exposure to thiols and amines. Thiols cause positive resistivity change, while amines cause negative resistivity change. Thinner nanowire fabricated by EBL showed higher sensitivity.