Creatinine Detection by Surface Plasmon Resonance Sensor Using Layers of Cerium Oxide and Graphene Over Conventional Kretschmann Configuration

In this study, creatinine in solutions at varied concentrations (non-enzymatic samples) is detected utilizing a surface plasmon resonance (SPR) sensor design. The presence of creatininase enzymes in the creatinine solutions (enzymatic samples) was used to evaluate the sensor's performance. An optical wavelength of 633 nm was used in the angular interrogation technique. The proposed SPR sensor detects the presence of creatinine in blood samples ranging from 10 to 200 mM. The goal of researching the enzymatic sample was to improve the sensor's sensitivity to creatinine in the samples. The non-enzymatic creatinine sample had a sensitivity of 18.42 Degree/RIU, and for creatinine-creatininase, the enhanced sensitivity of 250 Degree/RIU has been achieved when exposed to 633 nm optical wavelength. The increased sensitivity may be owing to an increase in the refractive index of the analyte sensing layer because of creatinine-creatininase coupling activity.