Ultrasensitive label-free electrical detection of charged biomolecules using a metal-semiconductor-metal Schottky silicon nanowire biristor

摘要

An open-base metal-semiconductor-metal Schottky silicon nanowire (MSM-SiNW) biristor device is applied for ultrasensitive, label-free, real-time electrical detection of pathogenic charged biomolecules. The detection technique is based on the modulation of the electrical properties when the biomolecules interact with the open-base region and is considered for the development of label-free biosensors that avoid the need for biomarkers before detection. The open base acts as a sensing site for the charged molecules that causes changes in the upper threshold latch-up voltage (V UT), the lower threshold latchdown voltage, as well as the latching window. To investigate the physics governing the device and its biomolecule sensing performance, mathematical simulations are carried out using calibrated two-dimensional (2D) technology computer-aided design software. The variation of V UT at different concentrations of charged biomolecules and polarities is studied in depth. The results demonstrate that the MSM-SiNW biristor has great potential as a biosensor based on its fast response time, scalability, simpler recovery mechanism, and greater sensitive even with smaller channel lengths. Further, it also demonstrates low-power operation, higher packing density, and coherent integration with existing manufacturing technology. The sensing behavior with silicon-germanium as the base semiconducting material is also investigate. This sensor design is expected to have a lower thermal budget as the doping process is no longer required. It has potential to be employed for array-based screening and in vivo biospecies diagnostics.