An efficient self-made paper-based carbon electrode for electrochemical detection of heavy metal ions

In this paper, a highly efficient self-made paper-based carbon electrode for the electrochemical detection of heavy metal ions was developed. The electrodes were fabricated on paper substrates by screen printing technology, and the electrochemical performance of which was subsequently improved by UV/ozone modification process. The surface morphology and chemical composition of the electrode was studied using scanning electron microscope and X-ray photoelectron spectroscopy. The electrochemical response of the electrodes to Cu2+, Cd2+, Pb2+ ions was measured using differential pulse voltammetry technology. First, single Cu2+, Cd2+ and Pb2+ ions varying the concentration of 1-256 mu M were detected using the modified screen-printing carbon electrode. A good linear relationship was shown between the oxidation peak current and concentration. Then, single Cu2+, Cd2+ and Pb2+ ion solutions with a concentration of 16 mu M were measured at 0, 5, 10 and 15 days using the same electrode. It is found the self-made electrode exhibited good repeatability and long-term stability. Finally, the mixed solution of Cu2+, Cd2+ and Pb2+ ions was determined. The oxidation peaks of Cu2+, Cd2+ and Pb2+ ions were found to be at around - 0.11, - 0.68 and - 0.45 V, respectively. The electrode demonstrated good selectivity. Based on the excellent long-term stability and high selectivity, the self-made electrodes can be a promising choice for practical applications in the detection of heavy metal ions in water.