A Sensor Based on Hollow, Octahedral, Cu2O‐Supported Palladium Nanoparticles – Prepared by a Galvanic Replacement Reaction – and Carboxylic Multi‐Walled Carbon Nanotubes for Electrochemical Detection of Caffeic Acid in Red Wine

Abstract

AbstractA novel nanocomposites prepared from hollow, octahedral cuprous oxide supported palladium nanoparticles (Cu2O‐PdNPs) through a facile galvanic replacement reaction and carboxylic multi‐walled carbon nanotubes (MWCNTs‐COOH) was modified on the surface of glassy carbon electrode (Cu2O‐PdNPs@MWCNTs‐COOH/GCE) to fabricate a sensor for electrochemical detection of caffeic acid. The synergistic effect between Cu2O‐PdNPs and MWCNTs‐COOH exhibited remarkable electrocatalytic activity, higher selectivity and higher sensitivity toward caffeic acid. At optimized test conditions, the Cu2O‐PdNPs@MWCNTs‐COOH/GCE nanocomposites sensor revealed wider linear range of 0.006‐60 μM with a lower detection limit of 0.002 μM (S/N=3) for caffeic acid determination. Eventually, the proposed nanocomposites sensor was successfully applied to determine the concentration of caffeic acid in red wine samples.