High-Sensitivity Enzyme-Free Glucose Sensing and Enhanced Photocurrent Response by a Nanoporous CuO and CuO-ZnO Composite

Abstract

This study presents the synthesis and multifunctional performance of nanoporous CuO-ZnO composites prepared via a polymer-confined direct solution pyrolysis (PDSP) method. The fabricated materials exhibit a highly porous architecture with uniformly distributed p-type CuO and n-type ZnO phases, forming efficient p–n heterojunctions. Electrochemical investigations revealed that the nanoporous CuO–ZnO electrodes achieved a high sensitivity of up to 8 mA cm⁻² mM⁻¹ with a rapid response time as fast as 1 s for enzyme-free glucose sensing, significantly outperforming other types of copper oxide- and Au- or Cu metal-based sensors. Additionally, photocurrent analysis under simulated solar illumination demonstrated a 5.6-fold enhancement in photocurrent for the CuO-ZnO composite compared to ZnO alone, which is attributed to efficient charge carrier separation across the heterojunction and improved light harvesting enabled by the porous structure. These findings highlight the potential of PDSP-derived CuO-ZnO nanocomposites as dual-functional materials for electrochemical glucose sensing and solar-driven photocatalysis.