The possibility of ultrasensitive detection of biomolecules using silicon nanowire biosensor with structural optimization

Abstract

Silicon nanowire (SiNW) biosensors, operating as field-effect transistors (FETs), demonstrate remarkable capabilities for the ultrasensitive detection of specific biomolecules. Our prior work specifically explored the impact of SiNW widths on biosensor sensitivity, highlighting that narrower SiNWs significantly enhance detection sensitivity. While experimental studies provide valuable insights, theoretical investigations into the combined effect of multiple parameters on sensing performance are crucial. However, theoretical studies have been relatively scarce in the research of SiNW biosensors. In response to this gap, we developed a numerical model of SiNW biosensor using the finite-element method in COMSOL Multiphysics. By leveraging simulations, we explored the sensing performance of SiNW biosensors across various widths, thicknesses, impurity concentrations, and their combined effects, addressing a previously unexplored area in this research. Based on the simulations, the optimal structure that exhibits both high sensitivity and measurable current was predicted. To ascertain the reliability of our simulations, a subset of the results was compared with experimental data. Our findings indicate the potential for achieving ultrasensitive biomolecule detection using SiNW biosensors through structural optimization.