Renewable and Ultralong Nanoelectrochemical Sensor: Nanoskiving Fabrication and Application for Monitoring Cell Release

Nanoscaled electrode has been attracting increasing attention because of striking fundamentals and practical applications. Usually, the nanoscaled electrode is fabricated by manual or photo or electron-beam lithography, which is not easy to reproducibly fabricate with simple equipment. In this paper, a cost-effective method, nanoskiving, is developed to fabricate an ultralong nanowire electrode (ULNE). The ULNE is reproducibly obtained by simply sectioning a sandwich epoxy block with a Au film. The width of ULNE could be down to nanometer dependence on the thickness of the Au film, while the length could reach to the millimeter. Thus, the created Au ULNE shows steady-state microamperometric current, characteristic of the nanoelectrode array attributed to its macroscopic length and nanoscaled width without considering the overlap of the diffusion layer of the neighboring nanoelectrode. The electrodeposited Pt/Au ULNE displays unusual electrocatalytic performance toward both the oxidation and reduction of hydrogen peroxide and, as a nanosensor, gives rise to high sensitivity and selectivity of monitoring hydrogen peroxide released from cells stimulated by ascorbic acid.