Comparison of Copper(II)\nOxide Nanostructures with\nDifferent Morphologies for Nonenzymatic Glucose Sensing

Abstract

The\nglucose sensitivity achieved with copper(II) oxide particles\nwith three different morphologies (spheres, platelets, and needles)\nfor application in nonenzymatic glucose sensors was investigated.\nThe morphologies of CuO nanoparticles were controlled by different\nsynthesis parameters, including changes in precipitators of Cu(II)\nions, pH values, calcination protocol, and the addition of surfactant\nand hydrogen peroxide. The role of copper(II) oxide particle morphology\nin nonenzymatic glucose sensing was studied. The primary driving factor\nin the electrocatalytic process was investigated for several morphological\nproperties of the material. We studied the effects of exposed crystal\nfaces, specific surface area, pore volume, and grain size of copper\noxides on glucose sensitivity. This study showed that the electrocatalytic\nperformance in glucose sensing correlates primarily with the grain\nsize of copper oxide nanoparticles and the capacitance introduced\ntherefrom. The needle-shaped CuO nanoparticles presented the optimal\nmorphology in this application, resulting in good sensitivity to glucose\n(2.05 mA·mM^–1·cm^–2),\na linear range of 0.05–5 mM glucose, and the best long-term\nstability among these materials. This work provides insight into the\npotential use of CuO-based materials in biosensors and into the major\ncontributing factors of metal oxide-based nanoparticles in sensing\napplications.