Rapid and highly selective surfactant-free lead(II) ion-imprinted nanoparticles for preconcentration with negligible...

Lead pollution is a critical environmental problem and has significant adverse health effects. Lead continues to enter the environment from industrial processes, despite regulation. Traditional techniques for detecting and removing Pb²⁺, especially at trace levels, are generally ineffective and non-selective. Ion-imprinted polymers (IIPs) for Pb²⁺ detection and removal are promising new materials, as they are selective, adsorptive, and reusable. In this work, a novel Pb²⁺-imprinted polymer nanoparticle, was synthesized using quinizarin-based ion-imprinting chemistry and was introduced for effective Pb²⁺ detection and removal.

The IIP nanoparticles were prepared by complexing quinizarin with Pb²⁺ in dimethylformamide, followed by polymerization with ethylene glycol dimethacrylate. Characterization using ICP-AES, infrared spectroscopy, SEM, and elemental analysis indicated successful polymerization and the formation of Pb²⁺-selective cavities. The uptake of Pb²⁺ was maximized at pH 5.0, showing a rapid adsorption rate (within 5-30 min) and a maximum capacity of 146.9 μmol g^-1, corresponding to a preconcentration factor of 17.8. Competitive sorption experiments demonstrated high selectivity for Pb²⁺. Desorption using 0.1 M hydrochloric acid yielded 98.5% recovery of the ion. The polymer exhibited high reusability over six cycles with a relative standard deviation of 1.9% and a detection limit (3.3σ) of 2.6 ng mL^-1.

The synthesized Pb²⁺-imprinted polymer offers a highly efficient, selective, and reusable approach for Pb²⁺ removal and detection in complex water systems.Its rapid sorption/desorption kinetics, high reusability, and strong selectivity present a highly applicable technique for environmental monitoring and water purification, providing a sustainable method for treating lead contamination down to trace levels.