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

Abstract

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 (I(cp)) in a biosensing operation. The maximum tunneling distance (d(tunnel)) of the electrons is the dominant factor to determine the amount of generated I(cp), 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 d(tunnel), in this case the nanogap height, frequency of the applied pulse, and maximum pulse level, are analyzed. (C) 2010 American Institute of Physics. [doi:10.1063/1.3443580]