A Highly Sensitive Long-Range Surface Plasmon Resonance Biosensor for the Determination of Hemoglobin Content in Human Blood

A surface plasmon resonance (SPR) biosensor with Kretschmann configuration and wide-range detection capability for measuring hemoglobin content in human blood has been proposed. The biosensor utilizes BK7 prism/Ag/α-SnSe/Ag/graphene architecture to detect hemoglobin concentration in human blood samples. The graphene layer was incorporated into the original structure to enhance the sensitivity of the device. Furthermore, layers were optimized, and the transfer matrix method determined the device’s reflectance. A high sensitivity of 184 degree.RIU−1 was obtained for the original structure, which increased to 187 degree.RIU−1 after including one graphene layer at a refractive index (RI) of 1.34 and 1.37. It was also found that incorporating more graphene layers enhanced the selectivity further, which came at the expense of compromising the quality factor.