Enhanced 1D photonic crystal biosensor for blood components and blood infection detection

The present work proposes a unidimensional asymmetric photonic crystal (1D PhC) sensor suitable for detecting blood components for both healthy and infected conditions. The proposed design is an enhanced efficient biosensor that distinguishes five blood components, namely; platelets, plasma, haemoglobin, RBCs and WBCs. The present work biosensor is designed as N binary nanostructured layers of SiO2 and PbS, with a defect layer, D, to form an asymmetric (P|Q)N/2D (P|Q)N/2 model. Infrared radiation is directed on the PhC in two cases: (i) normal incidence and (ii) oblique incidence with transverse electric mode (TEM) and transverse magnetic mode (TMM). The EMW propagation through the PhC layers is simulated using the well-established transfer matrix that is implemented using MATLAB software. The present work PhC design produces output transmission pulse peaks for all samples under investigation, both healthy and infected. The sensitivity, S, FoM, FWHM and Qf are calculated to assess the proposed biosensor performance. The presented biosensor exhibits better sensitivity (S), in the case of oblique incidence (TEM) than the normal incidence. Moreover, the performance of the proposed biosensor is validated by calculating another type of sensitivity (S ') for the five infected blood-component samples when related to their corresponding healthy ones. Furthermore, the variation of sensitivity with the angle of incidence is investigated showing a significant rise in the sensitivity with the increase in the incident angle. The proposed biosensor exhibits maximum sensitivity; Smax = 625.0 nm/RIU for infected plasma in the case of normal incidence, while Smax = 1025.4 nm/RIU for infected Hb (TEM) and Smax = 675.0 nm/RIU for infected WBCs (TMM). The proposed PhC biosensor is capable of early detection of some diseases such as leukaemia, dengue virus and malaria. The proposed biosensor performance is compared to recent literature exhibiting higher sensitivity, thus presenting an accurate method of further blood disease detection.