BACKGROUNDCuS nanocrystals with excellent properties are widely applied as semiconductor materials, but little work has been done on their application to electrochemical analysis. This paper reports on a very straightforward method to synthesize pure hexagonal phase CuS nanocrystals with an average diameter of 20 nm by a solvothermal method. A glassy carbon electrode was modified by drop casting the suspension of CuS nanocrystals and chitosan onto its surface. The new electrochemical sensor was developed for the determination of hydroquinone. RESULTSThe crystallization, morphology and composition of as-prepared CuS nanocrystals were characterized by XRD, SEM, Raman and EDS, respectively. The electrochemical oxidation behavior of hydroquinone at a CuS nanocrystals/chitosan/glassy carbon electrode was investigated by cyclic voltammetry. The electrode exhibited a wide linear dynamic range between 4.5 mu mol L-1 and 4.5 mmol L-1 hydroquinone, and a detection limit of 1.5 mu mol L-1. CONCLUSIONSThe electrode was successfully applied to the determination of hydroquinone in real water samples with satisfactory accuracy and precision. (c) 2013 Society of Chemical Industry