Si/SiO2 Based Nano-cavity Biosensor for Detection of Anemia, HIV and Cholesterol Using Refractive Index of Blood Sample

Abstract

Objectives: To model photonic multipurpose biosensor for detection of sickle cell anemia, HIV and cholesterol by its refractive index using FDTD method. Methods: The proposed multipurpose photonic biosensor has 12mm X 08mm dimension designed using Lumerical software. Blood sample is deposited inside the hole cavity of sensor and gaussian light source of 1.5 – 1.6 mm wavelength is injected inside the waveguide, based on the refractive index of disease sample to the normal sample there will be shift in the wavelength. FDTD method is used for simulating the PhC silicon sensor. When body gets infected there will be changes in physical as well as biological composition results in disparity of refractive index of biological component. Resonating frequency will be displayed in DFT monitor at the output waveguide. Findings: Based on the RI value the resonating wavelength shifts inside the bandgap of frequency spectrum. By comparing with the normal value there is shift in wavelength of 03nm, 08nm and 22nm for anemia, HIV and Cholesterol respectively. Biosensor has Quality factor of 257, tolerance factor 3% and the sensitivity obtained for change in RI of the sample is 225 nm/RIU. Novelty: The proposed biosensor functions as multipurpose detector and design is compatible in detecting anemia, HIV and Cholesterol in photonics platform. Novel signature analysis is performed by using polar plot for distinguishing the disease in early stage. Keywords: Photonic Crystal; Refractive index; Red blood corpuscles; Human immunodeficiency virus; Finite difference time domain; Photonic bandgap