Electrochemically activated copper nitroprusside as a catalyst for sensing of carcinogenic acetaldehyde in red wine

Acetaldehyde (AcH) is a carcinogenic, neurotoxic and genotoxic volatile organic compound present in beverages and pose hazardous effects on human health. Herein, we report electrochemically activated copper nitroprusside (CuNPr)-based sensor for the ultra-trace detection of AcH. CuNPr was synthesized by simple co-precipitation method and its physicochemical properties were characterized using spectroscopy and microscopy techniques. CuNPr-modified glassy carbon electrode (CuNPr/GCE) has been electrochemically activated prior to deploying for AcH sensing. The influence of electrochemical activation and supporting electrolytes (LiCl, NaCl, KCl, CsCl, KNO3, Na2HPO4/NaH2PO4, K2HPO4/KH2PO4) have been investigated. A better sensitivity of the sensor was obtained with potassium phosphate (K2HPO4/KH2PO4, pH 7.4) buffer. The electrochemical oxidation of AcH to acetate ions by CuNPr has been studied using in-situ spectroelectrochemical (UV absorption and Raman spectroscopy) analyses. Under optimized differential pulse voltammetric conditions, electrochemically activated CuNPr/GCE exhibited a wide linear range (2.5 × 10−8 – 2.5 × 10−1 M) with a limit of detection towards AcH as low as 41 × 10−8 M. The developed CuNPr/GCE sensor was employed for the sensing of AcH in undiluted commercial red wine sample and found to have good stability and anti-interference ability towards various co-existing ions in undiluted red wine.