Direct Laser-Induced Hierarchical Mesoporous Copper Oxide on Copper Surface for Electrochemical Sensing

In this work, we demonstrate a novel a one-step rapid laser-processing approach for the fabrication of electrochemically active copper oxide mesoporous structures directly on copper metal surfaces. The effect of laser processing power on the composition, crystallinity, microstructure, wettability and color of the laser-induced oxide on the copper surface was systematically studied using optical microscopy, scanning electron microscopy (SEM), grazing incidence X-ray diffraction, Raman spectroscopy, and water contact angle measurements. The created ratio and percentage of crystalline Cu2O [111] and amorphous CuO with different laser processing conditions was confirmed by GI-XRD and Raman spectroscopy. Results of these studies confirmed clear decrease in size of created copper oxide nanostructures and increase in overall crystallinity of the final surface with increase in laser power processing conditions. The optimized copper oxide electrodes with the highest surface area and crystallinity showed the ability to be used for nonenzymatic glucose and hydrogen peroxide sensing with a unique ultrahigh sensitivity, fast response/recovery time, and selectivity. This rapid laser-induced oxidation technique can be potentially applied for scalable fabrication of wide range of electrochemically active metal oxide micro/nanostructures directly onto different metal surfaces for potential used in other electrochemical and biochemical sensing applications.