The use of copper(II) oxide nanorod bundles for the non-enzymatic voltammetric sensing of carbohydrates and hydrogen peroxide

CuO nanorod agglomerates were synthesised via a simple hydrothermal method in the presence of polyethylene glycol (PEG; M_w 20,000). The chemical composition, size and morphology of the prepared CuO material was investigated by X-ray powder diffraction, voltammetry and transmission electron microscopy. A basal plane pyrolytic graphite electrode (bppg) was modified with the CuO nanorods and used to study the direct oxidation of glucose, fructose and sucrose in an alkaline medium (0.1 M NaOH). The CuO nanorod modified electrode was shown to have far larger analytical signals in the presence of carbohydrates than an electrode modified with CuO microparticles and gave a limit of detection for glucose of 1.2 × 10^-6 M which is comparable with the literature. As such it is a non-selective, non-enzymatic, total carbohydrate sensor. The CuO nanorod modified bppg electrode was also used for the detection of H₂O₂, it was shown that in this case it is preferential to look at the oxidation of the analyte due to interference of oxygen in the reductive window. A limit of detection of 2.2 × 10^-7 M was obtained for the sensing of hydrogen peroxide in an alkaline solution.