Sensing of Prostate-Specific Antigen Using Trimmed Silicon Nanowire Field Effect Transistors

Abstract

A field effect transistor (FET) biosensor with a trimmed silicon nanowire (SiNW) structure was designed, fabricated, and characterized for the selective and real-time detection of the prostate-specific antigen (PSA), a biomarker for diagnosing prostate cancer. The SiNW FET was fabricated using only top-down CMOS process techniques, including photoresist trimming. To detect PSA, the SiNW surface was modified with an antibody of PSA (anti-PSA). The sensing of PSA then occured via real-time conductance changes of the SiNW. The output response of the SiNW FET biosensor was linearly related to the PSA concentration within a range of 50 pg/ml and 500 pg/ml. When investigating the selectivity, the SiNW modified to detect PSA did not respond to the C-reactive protein (CRP). Thus, the results demonstrated the feasibility of the proposed biosensor for diagnosing prostate cancer.