GaAs/Ge polarity controlled TFET biosensor for SARS-CoV-2 detection: a simulation-based study

The Severe Acute Respiratory Syndrome Co-ronavirus 2 (SARS-CoV-2) epidemic has raised significant public health concerns due to its rapid global spread. Currently, there are no effective treatments or vaccines available for SARS-CoV-2, making early detection essential for controlling outbreaks and reducing casualty rates. This study presents a feasibility assessment of a GaAs/Ge Polarity Controlled Tunnel Field-Effect Transistor (GaAs/Ge PC-TFET)-based biosensor designed for the rapid detection of SARS-CoV-2. The proposed GaAs/Ge PC-TFET biosensor detects SARS-CoV-2 in clinical samples by determining the equivalent dielectric constants (k) of the SARS-CoV-2 spike protein (S-protein) and DNA. The sensor’s electrical properties change significantly when SARS-CoV-2 is immobilized within its nano-cavity region. The sensitivity of the GaAs/Ge PC-TFET biosensor is evaluated in terms of drain current (I_DS), threshold voltage (V_Th), subthreshold slope (SS), and the ON/OFF-current (I_ON/I_OFF) ratio, with respect to the k-value and charge density ( \(\rho\) $\rho$ ) of the SARS-CoV-2 virus. Additionally, this study analyzes the biosensor’s performance considering non-ideal immobilization issues, thermal drift, and environmental noise. Technology Computer-Aided Design (TCAD) software was employed for the implementation and simulation of the proposed GaAs/Ge PC-TFET biosensor. Ultimately, the proposed GaAs/Ge PC-TFET biosensor holds promise as a diagnostic device for the quick and accurate detection of SARS-CoV-2 from patient saliva samples.