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; Mw 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.