Fluorescence signal amplification of gold nanoclusters with silver ions

Abstract

The introduction of Ag⁺ results in significant amplification of the fluorescence signal of water-soluble gold nanoclusters (NCs) capped by BSA (short for bull serum albumin) associated with a blueshift of the emission maximum by about 35 nm. In contrast, all other metal ions and anions (Au³⁺, Ca²⁺, Mn²⁺, NO₂⁻, F⁻, Cl⁻, etc.) induce comparable emission intensities, and Hg²⁺ completely quenches the emission of gold NCs. The amplified fluorescence is used to recover the fluorescence in sensing systems of Hg²⁺ based on gold nanoclusters, amplifying the emission signal and improving the detection limits.