Nickel-functionalized reduced graphene oxide with polyaniline for non-enzymatic glucose sensing

We have developed a new class of organic-inorganic hybrid nanostructures based on the use of reduced graphene oxide (rGO), polyaniline, and a nickel metal nanostructure. It was applied to efficient non-enzymatic sensing of glucose based on its electrocatalytic oxidation. Scanning electron microscopy and energy-dispersive X-Ray were employed to characterize the material. It is shown that the doped polyaniline plays an important role in the formation of the hybrid nanostructures. Improved analytical performance is found when the hybrid nanostructures were placed on a glassy carbon electrode and used for non-enzymatic sensing of glucose at a typical working potential of +450 mV and a pH value of 13. Features include a fast response (similar to 2 s), high sensitivity (6,050 mu A mM(-1) cm(-2)), a linear range from 0.1 mu M to 1.0 mM, and a low detection limit (0.08 mu M). The response to glucose follows a Michaelis-Menten kinetic behavior, and the K (M) value was determined to be 0.241 mu M. Reproducibility and specificity are acceptable. Fructose and maltose do not interfere significantly. Importantly, the methodology was validated and evaluated for the analysis of 15 spiked human serum specimens, receiving in a good accordance with the results obtained by the non-enzymatic glucose sensing and the commercialized personal glucose meter.