Preparation of Iron Doped Polymeric Dopamine Micro/Nanosphere and Its Application in Lead Ion Electrochemical Sensing

Monitoring of heavy metal ions Pb²⁺ is a meaningful topic due to their high toxicity and serious damage on human health and ecological environment. In this paper, iron doped polymeric dopamine micro/nanospheres modified glassy carbon electrodes (Fe@PDA/GCE) were prepared and for the first time applied in heavy metal Pb²⁺ detection. Differential pulse voltammetry (DPV) method was used for the quantitative determination of lead. The results showed that Fe@PDA/GCE exhibited excellent detection performance for Pb²⁺, with a wide concentration response linear range of 0.05–110 μM (10.4–22 792 μg L^–1) and a low detection limit of 2.9 nM (0.6 μg L^–1) (S/N = 3). This performance is comparable to or even superior to the reported electrochemical platforms for Pb²⁺ determination. We attributed the improvement to the enrichment effect and charge transfer ability of Fe@PDA toward Pb²⁺. Fe@PDA/GCE also shared many advantages such as good reproducibility, anti-interference capability and low cost, allowing actual samples detection with recovery 95.9–104.0% and RSD 1.8–2.2%. Therefore, the Fe@PDA/GCE electrochemical sensors have good application prospect in water environment monitoring.