Voltammetric Determination of Copper Ion in Water Samples Using a dro‎p Casted Biopolymer

Poly-dopamine, inspired by biopolymers of mussels, is an adhesive catecholamine possessing low cytotoxicity and very good biocompatibility. In the present study, poly-dopamine nanoparticles (PDNP), as a biopolymer, were synthesized and characterized using FTIR spectroscopy, scanning electron microscopy and electrochemical methods. The drop casted PDNPs at the surface of carbon paste electrode (CPE) shows a great tendency to form complexes with Cu(II). This fact was selected for determination of Cu(II) in water. Copper exists broadly in various oxidation states in nature. It is also as one of the most harmful pollutants in the environment due to its nondegradability, high toxicity and bioaccumulation and so its determination is demanded. X-ray photoelectron spectroscopy (XPS) was applied to clarify the interaction. The influential parameters affecting Cu(II) binding were optimized including adsorption time, pH, and stirring speed. In optimum condition, differential pulse voltammetry was exploited for analytical determination of Cu(II) in the ranges of 1.0-100 μM and 0.05-1.0 μM with the limit of detection 0.04 μM. The sensor ability for copper determination in water samples was also demonstrated.