Nanoarchitectonics with NADPH Catalyst and Quantum Dots Copper Sulfide on Titanium Dioxide Nano-sheets Electrode for Electrochemical Biosensing of Sorbitol Detection.

Sorbitol accumulation in the tissue is known to cause diabetic complications. Nanotechnology-enabled biosensor methods have high sensitivity, selectivity, and more rapid detection of an analytic for sorbitol which is used as a biomarker of diabetic complications. The biosensor used aldose reductase from serum blood to oxidize the NADPH by the enzymatic reaction and reduce glucose to sorbitol. Biosensors can be developed for diagnostic testing. Developing a simple, sensitive, and rapid method for sorbitol detection is significant for efficient monitoring of diabetic complications like neuropathy at the initial stages. This project synthesized quantum dots of copper sulfide (CuS QDs) to fabricate an Electrochemical sensor for the detection of sorbitol by the UV-irradiation technique. The crystal structure of CuS QDs was characterized using X-ray diffraction (XRD), which confirmed the synthesized sample's hexagonal shape. The structure of the manufactured product was examined using energy-dispersive X-ray spectroscopy (EDX), and the result revealed just copper (Cu) and sulfide (S) elements, indicating that the synthetic material was pure. The morphology, optical properties, and particle size were investigated by scanning electron microscope (SEM), photoluminescence spectroscopy (PL), and transmission electron spectroscopy (TEM), respectively. The particle sizes of the CuS QDs were found to range between 5.4 to 9.1 nm. The CuS QDs will be dedicated to the conventional methods to synthesize the modified electrode functionalized with NADPH and covered with CuS QD (Ti-TiO2/CuS/NADPH) demonstrated switchable interfacial properties. The electrochemical process was characterized by cyclic voltammetry (CV). The developed sensor was successfully tested to detect sorbitol in human serum samples. The high catalytic activity and the redox behavior of CuS QD make it an efficient matrix for the realization of sorbitol. These results indicate that CuS QD is a suitable candidate material for developing enzyme-based sorbitol biosensors.