Abstract
Protein plays a crucial role in building and repairing tissues so it is vital to develop a sensitive and rapid detection biosensor that can detect the concentration of protein in an aqueous solution. For biosensing applications, photonic sensing is a revolutionary technique that allows accurate measurement. The current work presents a defective ternary photonic crystal based on Si/ Si3N4/ SiO2 layers with a central cavity filled with a solution sample of protein. The photonic structure is employed as a biosensor for protein detection in an aqueous solution. The transfer matrix method (TMM) is used to analyze the photonic structure. The sensitivity of the photonic structure is investigated with the variation of the cavity thickness and the angle of incidence to achieve a high performance of the biosensor. The results reveal that the defect mode localization moves to a lower wavelength region with increasing the angle of incidence while it shifts toward a larger wavelength region with increasing the thickness of the defect layer. Ultra-high sensitivity of 2488.98 nm/RIU is obtained with an angle of incidence of 60 degrees and cavity thickness of 4.5 mu m. The suggested photonic structure's simplicity makes it suitable for industrial design employing low-cost and large-scale product nanofabrication processes. It can be used as a biosensor not only for protein detection but for a broad range of purposes in the field of biosensing.