Cleaved disulfide cross-linking functionalized silica nanoparticles for enrichment of Cd (II)

We successfully introduced a cleaved disulfide on the surface of silica nanoparticles (SNPs), which can be used to enrich Cd (II) ion in aqueous solution. Firstly, the thiol-coated SNPs reacted with 4,4′-dithiodipyridine to form disulfide linkage on the surface of nanoparticles, then benzimidazole molecules were grafted on the surface via a cleaved disulfide linkage. TEM, FT-IR and XPS were used to characterize the process of preparation. After Cd (II) was adsorbed and enriched, the disulfide linkage was cleaved by addition of reduced glutathione solution. The enrichment results showed that the concentration of Cd (II) increased around 10 times as much as initial solution, which suggesting that the cleaved SNPs have a good capacity of enrichment of Cd (II).