Ion-Sensitive Field-Effect Transistor-Based Biosensor for PSA Antigen Concentration Measurement Using Microfluidic System

Prostate cancer is one of the most common cancers in men. Prostate-Specific Antigen (PSA) is an important biomarker in the diagnosis of prostate cancer. In the present paper, an Ion-Sensitive Field-Effect Transistor (ISFET) is introduced, employing microfluidic technology to detect PSA antigens efficiently. PSA antigen is our analyte in this sensor. Due to the PSA antigen's acidity and sensor sensitivity to the hydrogen ions and pH index, absorbing the hydrogen ion by the OH receptor on the sensor surface modulates the drive current and the device's threshold voltage. The electroosmotic flow is induced inside the microchannel by applying a voltage to the electrodes on the walls of the microchannel. Consequently, turbulence in the fluid flow in the channel has occurred that effectively moves the intended analytes toward the sensor surface. The biosensor performance is investigated by the simulations carried on in COMSOL. Our simulation results indicate that the proposed structure facilitates rapid detection and measurement of PSA concentration.