Label-free glucose biosensor based on 1D photonic crystal containing 2D GaSe

Label-free biosensors based on photonic crystals have attracted significant attention due to their high accuracy and sensitivity in measuring blood glucose concentrations. In this article, a one-dimensional photonic crystal containing two-dimensional gallium selenide and mica (KAl 2 (Si 3 AlO 10 )(OH) 2 ) layers, along with glucose as the defect layer, is analyzed using numerical simulation based on the transfer matrix method. The properties of the studied photonic crystals show that increasing the glucose concentration from 1 to 1000 mg/dL shifts the wavelength of the defect mode towards longer wavelengths. The maximum sensitivity of the sensor was found to be 8495.25 (nm/RIU) in which the glucose concentration is 1 mg/dL. In addition to sensitivity, the biosensor demonstrates a high quality factor (Q~3×10 8 ) which is reflects superior spectral resolution. It can also be used for various biosensing applications beyond glucose detection and pave a way to designing next-generation optical biosensors based on 2D materials for biomedical applications.