Theoretical study of hybrid multifunctional one-dimensional photonic crystal as a flexible blood sugar sensor

Photonic sensing is a novel technology and accurate measurement for biosensing applications. The present work proposes a defective one-dimensional photonic crystal (1D-PC) based on Si/SiO2-layers with a central liquid-filled defect layer as a blood sugar concentration biosensor in the visible region. The transmission spectrum is calculated numerically by using the transfer matrix method. The thickness of the defect layer and incident angle are optimized to achieve the best performance of the sensor. The results show that the localization of defect mode shifts to a longer wavelength with increasing the defect layer thickness. In addition to increasing the incident angle from theta(0) = 0 degrees to theta(0) = 90 degrees, the defect peak was shifted towards the short wavelength region. The optimized value of our structure demonstrates high sensitivity for the blood sugar (S = 1100 nm/RIU) in the range of concentration 0-500 mg dl(-1), more enhancement of the quality factor (3.539 x 10(6)) and very low limit of detection (8.8.x 10(-9) RIU) are achieved. Our results indicate that the proposed structure has higher performance as a blood sugar sensor than many previously reported data. Besides, the simplicity of the proposed structure makes it favorable to the industrial design using inexpensive and massive product nanofabrication techniques.