A highly efficient organophosphorus pesticides sensor based on CuO nanowires-SWCNTs hybrid nanocomposite

A new electrochemical sensor based on hybrid nanocomposite consisting of copper oxide nanowires (CuO NWs) and single-walled carbon nanotubes (SWCNTs) was first developed for the detection of organophosphorus pesticides (OPs). The surface morphology, chemical composition and crystal structure of the hybrid nanocomposite were studied by SEM and XRD. The hybrid nanocomposite was highly stable and possessed special affinity for malathion, thus providing the basis for facile electrochemical quantification of malathion. The electrochemical behavior of the hybrid nanocomposites based sensor and its application for pesticides determination were first evaluated through cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Under optimized operational conditions, differential pulse voltammetry (DPV) was further employed for malathion detection, which shows a wide dynamic range with a limit of detection as low as 0.1 ppb (0.3 nM), good selectivity against other common pesticides, inorganic ions and sugars, as well as good stability and reproducibility. Its application for malathion-spiked liquid garlic samples was also demonstrated. These features implicate the potential applicability of CuO NWs-SWCNTs hybrid nanocomposites in sensitive and selective detection of organophosphorus pesticides.