SPR-Based Label-Free Sensor for RI-Based Detection of Urea Concentration

The real-time, label-free, and high sensitivity are the inherent advantages of surface plasmon resonance (SPR) technology, making it the most versatile tool for sensing the street. It has been extensively used in various fields such as healthcare, management of the environment, and food-borne diseases. In the last several decades, kidney-related issues become more serious and resulting in physical degeneration and even death. The glomerular filtration rate (GFR) defines the functioning of the kidney concerning blood filtration. The GFR rate gets degraded with the increase in urea concentration in human bodies. Therefore, this study presents a highly sensitive gold nanoparticle SPR sensor based on an angular interrogation method for the enzymatic detection of urea samples. The biocompatibility of the sensor is enhanced by functionalizing the sensor with layers of molybdenum disulfide (MoS 2 ) and cerium oxide (CeO 2 ). Exposing the sensor to analytes without any biocompatible layer achieves a maximum sensitivity of 186.50°/RIU. On the other hand, a maximum sensitivity of 217.50°/RIU and 275°/RIU is attained for Au/MoS 2 /urease and Au/CeO 2 /urease combinations, respectively.