la304835p_si_001.pdf (617.51 kB)
Synthesis of Highly Fluorescent Silver Clusters on Gold(I) Surface
journal contribution
posted on 2013-02-12, 00:00 authored by Mainak Ganguly, Anjali Pal, Yuichi Negishi, Tarasankar PalEvolution of fluorescence from a giant core–shell
particle
is new and synergistic, which requires both gold and silver ions in
an appropriate ratio in glutathione (GSH) solution. The formation
of highly fluorescent Ag2/Ag3 clusters on the
surface of AuI assembly results in giant AuIcore–Ag0shell water-soluble
microparticles (∼500 nm). Here, AuI acts as the
template for the generation of fluorescent Ag clusters. The presence
of gold under the synthetic strategy is selective, and no other metal
supports such synergistic evolution. The core–shell particle
exhibits stable and static emission (emission maximum, 565 nm; quantum
yield, 4.6%; and stroke shift, 179 nm) with an average lifetime of
∼25 ns. The drift of electron density by the AuI core presumably enhances the fluorescence. The positively charged
core offers unprecedented long-term stability to the microparticles
in aqueous GSH solution.