Gold nanoparticle-based fluorescent “turn-on” sensing system for the selective detection of mercury ions in aqueous solution

Abstract

In this study, a simple and straightforward fluorometric assay using dye-adsorbed gold nanoparticles (AuNPs) was used in the highly selective and sensitive detection of mercury ions in aqueous buffer solution. Through the strong affinity of Hg atoms for Au, Hg atoms in situ generated by the reduction of Hg(II) ions in the presence of citrate ions on the surface of AuNPs displaced cationic BODIPY dye (1-PPh₃⁺) from the fluorescence-quenched AuNP/1-PPh₃⁺ adsorbate, leading to a significant increase in fluorescence intensity. The AuNP/1-PPh₃⁺ adsorbate-based sensing system provided a rapid response upon the addition of Hg(II) ions, with highly fluorescent turn-on signals and excellent selectivity.