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

摘要

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 (H2O2). It has been found that Ni-Co (0.5:1) BMNWs/PC electrode exhibits superior non-enzymatic sensing ability toward H2O2 detection with a high selectivity. The electrode shows fast response within similar to 3 s and an excellent reproducible sensitivity of 2211.4 mu 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 mu M (S/N = 3.2) and a relatively long-term storage (50 d). Moreover, the sensor reveals excellent results for H2O2 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 H2O2 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.