Electrochemical sensor based on polystyrene sulfonate–carbon nanopowders composite for Cu (II) determination

•Electrochemical sensor based on composite of polystyrene sulfonate–carbon nanopowders.•A DPASV method with open circuit accumulation is developed for copper determination.•Accurate determination of copper at nanomolar concentration level is feasible.•The proposed method is successfully applied to mineral and environmental water samples.

A differential pulse anodic stripping voltammetric (DPASV) method, with an open circuit (OC) approach in the pre-concentration step has been developed for copper ion determination at very low concentration level using a sensor based on a polystyrene sulfonate–carbon nanopowders (PSS–CnP) composite. This composite material is easily prepared from ultrasonic assisted dispersions of CnP in aqueous solution of PSS. For preparation of sensor devices, a reproducible and inexpensive drop coating procedure of the surface of home-made pencil graphite electrodes (PGEs) using a CnP dispersion in PSS was performed. At the optimal conditions for accumulation (0.01 mol L−1 KNO3 at pH 3) and measurement steps (a reduction potential of −0.5 V for 60 s and then, an anodic DPV scan) and using a pre-concentration time of 300 s, the limit of detection was 0.11 µg L−1 (1.73 nM). This OC-DPASV method using the PSS–CnP–PGE sensor was successfully employed for Cu(II) determination in mineral, river and sea water samples.

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