In situ fabrication of CuO nanowire film for high-sensitive ascorbic acid recognition

One-dimensional metal oxides have been attracting interest as advanced materials for trace target recognition in chemical sensors due to their ultra-high surface area and electrochemical activity. However, the development of a large-scale and controllable fabrication strategy remains a great challenge and has hindered their practical application. In this work, we design a novel thermal oxidation route for obtaining a large area of CuO nanowires by the use of a film precursor of the nanocubic Cu-Fe Prussian blue analogue (PBA). The nanostructure and distribution of the PBA film was precisely controlled using an electrostatic self-assembly approach. The CuO nanowire shape was formed in-situ via the growth confinement effect through the air-heating collapse and oxidation of PBA crystals. At a very low working potential of 0.1 V, the as-prepared CuO nanowire sensor exhibited excellent sensing performance on ascorbic acid over a wide linear range (20-400 mu M) and a low detection limit (0.5 mu M), as well as high selectivity despite various interferences.