Ni and Co synergy in bimetallic nanowires for the electrochemical detection of hydrogen peroxide

Abstract The development of a highly sensitive and selective non-enzymatic electrode catalyst for the detection of a target molecule was remained a great challenge. In this regard, bimetallic nanowires (BMNWs) are considered as promising electrode material for their fascinating physical/chemical properties superior to a single system. In this article, nickel cobalt (Ni x –Co) BMNWs with tunable stoichiometry were prepared by a template assisted electrodeposition method and their catalytic performance was investigated for the detection of hydrogen peroxide (H 2 O 2 ). It has been found that Ni–Co (0.5:1) BMNWs/PC electrode exhibits superior non-enzymatic sensing ability toward H 2 O 2 detection with a high selectivity. The electrode shows fast response within ∼3 s and an excellent reproducible sensitivity of 2211.4 μ AmM −1 cm −2 , which is the best compared to the individual Ni, Co, Ni–Co (0.3:1) BMNWs and previously reported electrodes. In addition, the electrode shows a linear response in the wide concentration range from 0.005 mM to 9 mM, low detection limit of 0.5 μ M (S/N = 3.2) and a relatively long-term storage (50 d). Moreover, the sensor reveals excellent results for H 2 O 2 detection in the real samples. The enhanced sensitivity of the Ni–Co (0.5:1) BMNWs based electrode may be due to the stable structure and synergy of Ni and Co. The results demonstrate that the catalytic activity of the electrode binary catalyst towards H 2 O 2 detection can be improved by adjusting the Ni/Co ratio in BMNWs. The excellent performance of the electrode suggests that Ni–Co BMNWs are promising candidate for the construction of cost-effective electrochemical sensors for medical and industrial applications.