Rapid preparation of self-supported nickel-iron oxide as a high-performance glucose sensing platform

Nickel-iron based electrocatalysts that display a highly sensitive electrochemical response are promising candidates for non-enzymatic glucose sensors. In this work, we report a rapid (∼10 min) and controllable one-step electrodeposition of NiFeO x supported on nickel foam (NF) and carbon cloth (CC) as electrochemical glucose sensing platforms. Material characterization studies reveal that the as-electrodeposited NiFeO x is composed of tiny nanoparticles with a lower crystallinity degree and abundant oxygen vacancies. On the one hand, the lower charge transfer resistance allows NiFeO x /NF to achieve a fast charge transfer kinetics compared to pristine NF. On the other hand, NiFeO x /NF exhibits a larger double-layer capacitance ( C dl ) and superhydrophilic surface state, which result in an increased electrochemical surface area and enhanced affinity to glucose molecules. Consequently, the NiFeO x /NF glucose sensor presents a better sensing response (sensitivity: 2320 μA mM −1 cm −2 and the limit of detection: 0.094 μM in the linear range from 0.1-2.1 mM), an excellent selectivity against interfering substances, and high stability for over three weeks. In addition, the electrodeposition-derived NiFeO x is able to detect glucose in actual samples and also shows a promising prospect in flexible devices. This work not only offers a fast fabrication of the NiFeO x electrode but also highlights the potential use of Ni-Fe oxides for enzyme-free glucose sensing. Nickel-iron oxide electrocatalysts prepared via a rapid electrodeposition are promising candidates for non-enzymatic glucose sensors.