Development of a Nonenzymatic Glucose Sensor Operating in Neutral Media Using Pt-Cu Bimetallic Hydrogels

This study presents an electrochemical sensor for nonenzymatic glucose determination operating in neutral media using Pt-Cu bimetallic hydrogels. For preparation, a two-step reduction method was employed for the mixed metal precursors of Pt and Cu. The synthesized bimetallic hydrogels were characterized using scanning electron microscopy (SEM), energy dispersive X-Ray spectroscopy (EDS), X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), and electrochemical techniques. They featured a three-dimensional porous structure, good flexibility, and a high specific surface area. Under neutral pH conditions, the sensor exhibited high electrocatalytic efficiency toward glucose oxidation. It showed a rapid response to glucose at 0.2 V, with a linear detection range spanning 137 µM to 6 mM and retained considerable catalytic activity after one month. Significantly, it exhibited the same linear response up to 6 mM in diluted serum and artificial sweat samples. The sensor’s detection range covered the glucose concentrations in serum and sweat under physiological conditions, further demonstrating the feasibility of this nonenzymatic glucose sensor for real sample analysis and providing new insights for the research on nonenzymatic glucose sensors.