Ultrasensitive and selective non-enzymatic glucose detection using copper nanowires

Abstract

In the pursuit of more economical electrocatalysts for non-enzymatic glucose sensors, one-dimensional Cu nanowires (Cu NWs) with uniform size distribution and a large aspect ratio (>200) were synthesized by a facile, scalable, wet-chemistry approach. The morphology, crystallinity, and surface property of the as-prepared Cu NWs were examined by SEM, XRD, and XPS, respectively. The electrochemical property of Cu NWs for glucose electrooxidation was thoroughly investigated by cyclic voltammetry. In the amperometric detection of glucose, the Cu NWs modified glassy carbon electrode exhibited an extraordinary limit of detection as low as 35 nM and a wide dynamic range with excellent sensitivity of 420.3 μA cm(-2) mM(-1), which was more than 10,000 times higher than that of the control electrode without Cu NWs. The performance of the developed glucose sensor was also independent to oxygen concentration and free from chloride poisoning. Furthermore, the interference from uric acid, ascorbic acid, acetaminophen, fructose, and sucrose at the level of their physiological concentration were insignificant, indicating excellent selectivity. Finally, good accuracy and high precision for the quantification of glucose concentration in human serum samples implicate the applicability of Cu NWs in sensitive and selective non-enzymatic glucose detection.