Core-shell gold-nickel nanostructures as highly selective and stable nonenzymatic glucose sensor for fermentation process.

Non-enzymatic electrodes based on noble metals have excellent selectivity and high sensitivity in glucose detection but no such shortcomings as easy to be affected by pH, temperature, and toxic chemicals. Herein, spherical gold-nickel nanoparticles with a core-shell construction (Au@Ni) are prepared by oleylamine reduction of their metal precursors. At an appropriate Au/Ni ratio, the core-shell Au@Ni nanoparticles as a sensor for glucose detection combine the high electrocatalytic activity, good selectivity and biological compatibility of Au with the remarkable tolerance of Ni for chlorine ions (Cl-) and poisoning intermediates in catalytic oxidation of glucose. This electrode exhibits a low operating voltage of 0.10 V vs. SCE for glucose oxidation, leading to higher selectivity compared with other Au- and Ni-based sensors. The linear range for the glucose detection is from 0.5 mmol L-1 to 10 mmol L-1 with a rapid response time of ca. 3 s, good stability, sensitivity estimated to be 23.17 μA cm-2 mM-1, and a detection limit of 0.0157 mM. The sensor displays high anti-toxicity, and is not easily poisoned by the adsorption of Cl- in solution.