Axially-doped silicon nanowire field effect transistors for real-time sensing in physiologically relevant buffer solutions

This paper present the first measurements of chemically-gated axially-doped n+-p´-n+ silicon nanowire FETs and show stable and reproducible transfer characteristics in physiologically relevant buffer solutions (up to 100 mM KCl). The sensitivity of nanowire FETs having bare oxidized and chemically-functionalized surfaces to changes in pH was greatest when the devices were biased in the subthreshold regime during sensing. Silicon nanowire field effect transistors (FETs) are attractive biosensor candidates because they promise extremely high sensitivity and label-free, real-time detection.