Tailoring the glucose oxidation activity of anodized copper thin films†

Abstract

Glucose oxidation is a fundamental reaction in biosensing and energy conversion, and anodized copper electrodes have emerged as promising catalysts for its enhancement. This paper systematically investigates the link between anodization parameters and glucose oxidation on thin copper films, unraveling crucial insights into their optimization. By careful control of the anodization parameters, distinct species can be favoured, such as Cu₂O, Cu(OH)₂, and CuO, with varying catalytic activities. Applying a polarization in 1 M KOH at 0 V (vs. Ag|AgCl) results in the formation of a highly active surface CuO layer, which delivers significant performance improvements compared to the bare copper electrode. Namely, a 55% sensitivity gain in the 0.1–0.5 mM range, and a remarkable 73% gain in the 0.75–2 mM range. Furthermore, the manufactured electrodes display an extremely low limit of detection – only 0.004 mM. Such an exceptional result can be ascribed to the scalable and reproducible manufacturing done directly on cleanroom-compatible platforms. These insights not only clarify the effect of thin copper film anodization on glucose oxidation, but also chart a practical path towards improving the real-world efficiency of copper-based integrated systems for biosensing and energy conversion.