Cysteine-functionalized selenium nanoparticles for efficient extraction and preconcentration of cadmium, copper, lead, and zinc ions from environmental water samples

Abstract

This study aimed to develop cysteine-functionalized selenium nanoparticles (SeNPs) supported by γ-alumina (Al2O3@Se@Cys) for the effective extraction and preconcentration of cadmium, copper, lead, and zinc ions from river water and seawater samples. This one-pot synthesis method produced and functionalized SeNPs using L-cysteine as a green reducing agent. The different properties of Al2O3@Se@Cys were analyzed using various techniques, including Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray (EDX), and X-ray diffraction (XRD). Several experiments were conducted to identify and optimize the key variables influencing extraction efficiencies, such as the pH, ascorbic acid concentration, Al2O3@Se@Cys amount, solution volume, salinity, and elution and matrix clean-up conditions. The results showed that the proposed method provided detection limits ranging from 0.25 to 1.00 µg/L, relative standard deviations (RSDs, n = 5) between 1.1 % and 4.5 %, dynamic linear ranges within 10–200 µg/L (R2 ≥ 0.995), and enrichment factors >85. Moreover, the recoveries of the spiked standard solutions in river water and seawater samples were at least 94.0 %, with negligible interference from most major and minor ions commonly found in environmental water samples. The study demonstrated the successful development and application of Al2O3@Se@Cys, which exhibits a sustainable and eco-friendly approach to addressing environmental contamination challenges and highlights the expanding utility of SeNPs.