Hemoglobin biosensor for different blood groups using a topological photonic crystal mirror heterostructure

This work presents a hemoglobin (Hb) biosensor based on a topological photonic crystal (TPC) mirror heterostructure, which is evaluated using the transfer matrix method. The biosensor utilizes a topologically protected edge mirror state, exhibiting strong field confinement and robustness at the interface between two topological phases (TPCs). This edge state is susceptible to refractive index variations within a cavity introduced between the TPCs, into which blood samples are infiltrated. The refractive index of blood, modeled as a dispersive medium, varies with Hb concentration and temperature across different blood groups. The proposed biosensor demonstrates excellent performance; for blood group A, the maximum quality factor (Q) value reached is 9.38 × 10 4 , the sensitivity (S) is 117.93 nm/RIU, and the figure of merit (FOM) is 1.71 × 10 4 /RIU. It is also reported that Q, S, and FOM decrease as Hb concentration increases, but increase as temperature rises.