The effect of varied functional biointerfaces on the sensitivity of silicon nanowire MOSFET

A biocompatible and functional interface can improve medical applications of bioelectronic. Here, 3-aminopropyl trimethoxysilane (APTMS) and 3-mercaptopropyl trimethoxysilane (MPTMS) self-assembled monolayers (SAMs) were used to modify the surface of silicon nanowire (NW) -MOSFETs. AFM and electrical pH sensing verified which monolayer was capable of performing better electrical signal for subsequent immobilization of biomolecule. APTMS-SAM modified NW-MOSFETs showed more uniform modification on NW-MOSFETs and better electrical response to pH sensing. Biomolecule, such as antibody against prostate-specific antigen (anti-PSA), immobilized on APTMS-SAM modified NW-MOSFETs also successfully sensed those corresponding antigens in electrical measurement system. It elucidated that the suitable surface modification would profoundly affect the sensing response and sensitivity.