GST-Based Surface Plasmon Resonance Reconfigurable Biosensor for Detection of Human Sperm

In this paper, we propose a tunable surface plasmon resonance (SPR) biosensor using a phase change chalcogenide material (Ge₂Sb₂Te₅) by the transfer matrix method for the detection of human sperm samples. The growing challenge in natural reproduction lies in the heightened infertility of human sperm, attributed to fluctuations in environmental factors. Effectively tackling these concerning aspects requires the utilization of advanced computer-aided devices. However, the precision of such devices, particularly when dealing with low concentrations of sperm, is not meeting the required standards. The proposed SPR biosensor comprises layers of Ag, BaTiO₃, and GST for sperm detection. Achieving tunable and improved refractive index sensing along with a substantial figure of merit (FOM) is accomplished by transitioning the structural phase of GST from amorphous to crystalline. The sensing performances are assessed based on sensitivity, quality factor, detection accuracy, and FOM at a wavelength of 633 nm. The average angular sensitivity achieved is 236 deg/RIU for the crystalline phase and 286 deg/RIU for the amorphous phase, respectively. This sensitivity is observed within the dynamic range of refractive index (RI) spanning from 1.33 to 1.3461 RIU. The performance of our proposed SPR biosensor surpasses that of other reported works.