High-Sensitivity 3D ZIF-8/PDA Photonic Crystal-Based Biosensor for Blood Component Recognition.

Optical biosensors are sensitive devices used in bioanalytics detection. Analysis of blood constituents is very important for the detection of major diseases and also performs a significant role in the diagnosis of diabetes, various cancers, and cardiovascular disorders. In this work, a three-dimensional photonic crystal-based biosensor composed of zeolitic imidazolate framework-8 (ZIF-8) nanoarrays are placed on polydopamine (PDA) coated on a silicon substrate. This sensor is designed, simulated, and evaluated for various blood components in the wavelength range of 1.1 to 1.5 μm by the finite-difference time-domain (FDTD) method. The proposed biosensor was used for 10 types of blood components such as biotin-streptavidin, bovine serum albumin (BSA), cytop, glucose (40 mg/100 mL), hemoglobin, blood plasma, Sylgard184, white blood compounds, urethane dimethacrylate, and polyacrylamide. The FDTD technique was used for the performance analysis of the biosensor. The design parameters of the radius, the lattice constant, the thickness of the ZIF-8 arrays, and the PDA layer thickness are chosen to optimize the photonic crystal structure. This study indicates that the thickness of the PDA is the most important parameter for peak wavelength value in comparison to the other physical parameters. The factors for optimizing the photonic crystal-based biosensors such as the peak wavelength value (PWV), sensitivity, full width at half-maximum (FWHM), and figure of merit (FOM) are significant in comparison with pertinent works in this field, which evaluated 171 nm/RIU, 7.62 nm, and 22.5 RIU, respectively. A change of 0.01 nm in the refractive index of the constituents of the blood leads to a shift of 80 nm in the maximum peak wavelength, therefore acting as a functional biosensor with a high detection limit of 0.004 RIU.