Multi-mechanistic silica core-gold nanoparticles satellites for efficient mercury trace characterization in environmental media.

After several decades of research and observation of mercury dissemination in the environment, there is still some challenge to sample and analyze correctly in various matrices. This is specific to this element with various concentration and complex speciation with multiple bias from the sampling to the final quantification. Here, we present a highly effective silica core–gold nanoparticle satellites (Si@AuNP) structure that allow mercury capture through three comprehensive synergistic mechanisms: thiol complexation, citrate-mediated reduction, and direct amalgamation. Unlike conventional gold-based amalgam systems, our Si@AuNPs capture both Hg(II) and Hg(0) directly at the colloidal surface without requiring external reducing agents.