Annular photonic crystal biosensor for blood components and blood infections

The present work proposes an annular photonic crystal (APC) design that is adopted to distinguish and detect blood components. The proposed APC biosensor (APCB) is an accurate method of distinguishing healthy and infected blood constituents, namely platelets, plasma, haemoglobin, RBCs, and WBCs. The present work design consists of N cylindrical nanostructured binary layers with an air core, where a defect layer, D, is added to form (P|Q)^N/2D(P|Q)^N/2 design. The incident EMWs, in the near infrared region (NIR), are directed on the APC from a central axial antenna. The radial EMW propagation through the layers is simulated employing the well-established transfer matrix in cylindrical coordinates using MATLAB software. The proposed APCB parameters are initially determined by tuning the output transmission pulse peaks (TPPs) for all samples under investigation in the centre of the appropriate photonic band gap. Then, the biosensor sensitivity (S) is maximized by varying the defect layer thickness. Further performance enhancement is achieved by changing the nanostructured layers thicknesses. Moreover, the full-wave half-maximum (FWHM), figure of merit (FoM), and quality factor (Q_f) are calculated to evaluate the biosensor performance. The proposed APCB performance is validated by introducing another type of sensitivity (S’) for the five infected blood component samples referring to their corresponding healthy ones. The present work reaches maximum sensitivities of: S = 707.5 nm/RIU for infected plasma and S′ = 708.5 nm/RIU for Hb. This work introduces an APCB capable of early detection of five blood components and their infections. The unhealthy conditions detected by the proposed biosensor are dengue virus, malaria, and possible leukaemia. The proposed APCB in this work exhibits higher S and Q_f when compared to recent literature.