Preparation of Functionalized Magnetic Fe₃O₄@Au@polydopamine Nanocomposites and Their Application for Copper(II)...

Polydopamine (PDA) displays many striking properties of naturally occurring melanin in optics, electricity, and biocompatibility. Another valuable feature of polydopamine lies in its chemical structure that incorporates many functional groups such as amine, catechol and imine. In this study, a nanocomposite of magnetic Fe₃O₄@Au@polydopamine nanopaticles (Fe₃O₄@Au@ PDA MNPs) was synthesized. Carboxyl functionalized Fe₃O₄@Au nanoparticles (NPs) were successfully embedded in a layer of PDA through dopamine oxypolymerization in alkaline solution. Through the investigation of adsorption behavior to Cu(II), combined with high sensitive electrochemical detection, the as-prepared magnetic nanocomposites (MNPs) have been successfully applied in the separation and analysis of Cu(II). The experimental parameters of temperature, Cu(II) concentration and pH were optimized. Results showed that the as-prepared MNPs can reach saturation adsorption after adsorbing 2 h in neutral environment. Furthermore, the as-prepared MNPs can be easily regenerated by temperature control and exhibits a good selectivity compared to other metal ions. The prepared Fe₃O₄@Au@PDA MNPs are expected to act as a kind of adsorbent for Cu(II) deep removal from contaminated waters.