Si Nanowire Arrays FET Sensor and Interface Optimization Design for Ultrasensitive Protein Molecule Detection

This work proposes a CMOS-compatible label-free epidermal growth factor receptor (EGFR) biosensor based on 13 nm wide silicon nanowire (SiNW) arrays formed by a spaced image transfer (SIT) process. We overcome the Debye screening effect using a smaller molecule aptamer as the capture probe in order to reduce the thickness of the sensing layer and improve the interaction between the target molecule and the probe after capture through the optimization of the sensing interface. We demonstrate that the biosensor shows good stability, specificity, and a wide dynamic range (more than five orders of magnitude), and compared with traditional sensing technologies, our proposed Si nanowire field effect transistor (FET) biosensor provides a noninvasive, ultrasensitive, and stable method for fg/mL-level protein molecule detection. This will help us further understand cellular heterogeneity through single-cell protein analysis, which is expected to be used in molecular diagnostics.