New Biosensor Design Based on Photonic Crystal Core-shell Rods Defects for Detecting Glucose Concentration

Abstract

In this paper, an ultra compact photonic crystal (PhC) biosensor for detecting glucose concentration using resonant microcavity (RMC), sandwiched by two inline quasi-waveguides is investigated. The RMC is used as sensing region. It consisted of 7x7 core/shell (C/S) rod defects and 14 functionalized holes. The basic structure is formed by air holes arranged in hexagonal lattice in silicon (Si) background. The sensing mechanism of our biosensor is to detect the resonant wavelength shift, which is caused by the change of the refractive index (RI) of the shell layer and active holes filled with the analyte sample of glucose solution. The plane wave expansion (PWE) and finite difference time domain (FDTD) methods are chosen to analyze and simulate the performance of the suggested structure. The FDTD results reveal high sensitivity of 624.7904 nm/RIU with high linearity and quality factor. The presented sensor has a simple design and is easy to manufacture. In addition, the total size of the presented device is 92.65 µm2 which is very small for nanotechnology based sensing.