Determination of the Chemical Oxygen Demand Using a Cu-Au Anisotropic Nanoalloy-Modified Screen-Printed Electrode: A Sustainable and Sensitive Solution

Abstract

This study presents a new, non-enzymatic electrochemical sensor based on gold-copper nanobrambles (Au-CuONBs) for rapid and accurate chemical oxygen demand (COD) monitoring in water. COD, an essential metric of water quality, is typically assessed using labor-intensive methods with high toxicity and limited tolerance to chloride interference. The Au-CuONBs-based sensor here proposed overcomes these limitations by offering high sensitivity, a broad linear detection range (0.1-10.3 mM glucose), and robust tolerance to chloride ions, enabling accurate measurements even in challenging water samples. Tested on real wastewater samples, the sensor delivered results closely aligned with standard COD methods, with a detection limit of 11 mu M and response time of only 5 min. This portable, cost-effective sensor provides a promising solution for sustainable on-site COD analysis, enhancing water quality management and environmental monitoring.