Evolution of Silver-Mediated, Enhanced Fluorescent Au-Ag Nanoclusters under UV Activation: A Platform for Sensing

Here, we report the synthesis of dopamine (DA)-mediated Au-Ag bimetallic nanoclusters in aqueous solution under UV activation. The success story emerges from monometallic fluorescent nanocluster evolution from photoactivation of gold as well as silver precursor compounds along with DA. The intriguing fluorescence property of the nanocluster relates to facile incorporation of Ag in Au, showing a 6-fold enhancement of the emission profile than simply DA-mediated Au nanoclusters. Silver effect, which is classified under the synergism, is the main reason behind such enhancement of fluorescence. The as-synthesized nanoclusters are robust and can be vacuum-dried and redispersed for repetitive application. The intriguing fluorescence of bimetallic nanoclusters is found to be quenched selectively in the presence of sulfide ion in an aqueous medium, paving the way for nanomolar detection of sulfide in water. The utility of the sensing platform has been verified employing different environmental water effluents.