Silicon-based one-dimensional photonic crystal biosensor for the detection of prostate-specific antigen (PSA)

In this study, a one-dimensional photonic crystal (1D PC)-based refractive index biosensor for detecting prostate-specific antigen (PSA) is theoretically analyzed. A defective Si/SiO2 photonic crystal structure is proposed. The defect layer consists of healthy and prostate cancer blood samples to detect prostate-specific antigen (PSA). The variation in the refractive index (RI) of the analyte induces a shift in the defect mode resonance within the photonic band gap, forming the fundamental sensing mechanism of the proposed biosensor. The impedance approach was used to analyze the transmission spectrum. A high sensitivity of 3214.5 nm/RIU was achieved for the proposed biosensor. This structure has the potential for highly sensitive detection and sensing of PSA in human blood samples.