Protein detection capabilities of photonic biosensor composed of 1D annular photonic crystal

Present study examines the protein concentration detection capabilities of biosensor (AB)5D(AB)5 composed of a one-dimensional annular photonic crystal with defect theoretically. The simulation results of this work have been obtained by MATLAB programming based on the modified transfer matrix method. The entire simulation work has been carried out in the visible region of electromagnetic spectrum. The proposed biosensor (AB)5D(AB)5 is consisted of alternating cylindrical layers A and B of materials titanium oxide (TiO2) and silicon oxide (SiO2) respectively. The cylindrical cavity layer D of air is introduced at the centre of the biosensor so that sample under investigation can be poured into it. The study examines parameters such as defect cavity thickness, period number, and Core radius to optimise the biosensor for maximum protein detection performance. The performance of the proposed biosensor becomes optimum with the defect layer thickness 650 nm, period number 5 and Core radius 103 nm. Under optimum conditions biosensor yield maximum sensitivity of 576.27 nm/nmol/L corresponding to sample of protein concentration of c = 10 nmol/L. The numeric values of figure of merit, quality factor and limit of detection of the proposed biosensor 4432.85 nmol/L, 5630.76 and 1.1 × 10−5 respectively. The proposed design shows the ability to detect minute change in protein concentration of the sample of order 10−5. The structural symmetry and the simple implementation of our structure makes it suitable for clinical diagnostics and environmental monitoring.