Synthesis of fluorescent phenylethanethiolated gold nanoclusters via pseudo-AGR method

Abstract

It is well known that the fluorescence of metal nanoclusters is strongly dependent of the protecting ligand and reports of phenylethanethiolated metal nanoclusters with distinct fluorescence are rare. Herein, a fluorescent phenylethanethiolated gold nanocluster is synthesized using an unexpected pseudo-AGR method (AGR: anti-galvanic reduction). The cluster is precisely determined to be Au₂₄(SC₂H₄Ph)₂₀ by isotope-resolved mass spectroscopy in tandem with thermogravimetric analysis (TGA). The fluorescence comparison between Au₂₄(SC₂H₄Ph)₂₀, Au₂₅(SC₂H₄Ph)₁₈, Au₃₈(SC₂H₄Ph)₂₄ and Au₁₄₄(SC₂H₄Ph)₆₀ is also presented. The finding of the fluorescent phenylethanethiolated gold nanocluster in this work has important implication for future study on the fluorescence of metal nanoclusters.