Comprehensive study of a detection mechanism and optimization strategies to improve sensitivity in a nanogap-embedded biotransistor

A novel biomolecular detection method, charge pumping, is investigated comprehensively as a biosensing mechanism. Tunneling electrons located in channel interface are responsible for a charge pumping current (Icp) in a biosensing operation. The maximum tunneling distance (dtunnel) of the electrons is the dominant factor to determine the amount of generated Icp, which is closely correlated with the sensitivity in a proposed nanogap-embedded biotransistor structure. Using an analytical model in which biomolecules are considered as a trap-included insulator, the effects of the key parameters that govern dtunnel, in this case the nanogap height, frequency of the applied pulse, and maximum pulse level, are analyzed.