A core–shell AZO@ZnO nanostructure for accurate glucose detection with UV-boosted sensitivity

Abstract

Advances in micro-nano fabrication technology have enabled flexible electrochemical sensors to utilize micro-nanostructures and nanomaterials. Herein, a 3D AZO@ZnONRs core–shell nanostructure was synthesized using atomic layer deposition and hydrothermal techniques. The structure was employed to fabricate a high-sensitivity glucose sensor capable of precise detection of blood glucose levels and glucose content in sugary beverages. The sensor demonstrated a highly linear response (0–12.5 mM), with a sensitivity of approximately 6.49 µA·mM⁻¹·cm⁻² and a detection limit of 1.561 µM. Under ultraviolet light, the sensitivity increased by 1.83-fold. In the presence of interferents such as potassium chloride, sodium chloride, lactic acid, urea, and uric acid, the sensor maintained excellent specificity. Compared to conventional nanorods, this 3D core–shell material preserved the advantages of a high specific surface area while demonstrating enhanced electron transfer capabilities and photosensitivity, enabling reliable detection of glucose at extremely low concentrations. This study systematically analyzed the characteristics of the core–shell nanomaterial and its photocatalytic mechanisms, advancing photocatalytic electrochemical sensing technology.