WSe2 Negative Capacitance Field-Effect Transistor for Glucose Sensing

Field-effect transistor (FET) biosensors based on two-dimensional materials have been widely concerned in recent years because of their high sensitivity, label free, fast response and easy on-chip integration. However, constrained by the Boltzmann limit, the subthreshold swing (SS) of these sensors cannot fall below 60 mV/dec, posing challenges for further sensitivity enhancement. We present the biosensor based on a two-dimensional material WSe2 negative capacitance field-effect transistor (NCFET) with graphene electrodes, which achieves ultra-steep subthreshold swing (SS<60 mV/dec) in aqueous solution, while demonstrating extremely high glucose sensing sensitivity. At room temperature, WSe2 NCFET achieves a minimum subthreshold swing of 56 mV/dec in a liquid environment, and was used for the first time to detect glucose molecules with high sensitivity, wide detection range and specificity by enzymatic catalysis. The sensitivity of the WSe2 NCFET biosensor could reach 4800 A/A in a glucose solution with a concentration of 5 mM. This work inspires further basic research and potential applications for highly sensitive biosensors.