Simple fabrication of eptifibatide stabilized gold nanoclusters with enhanced green fluorescence as biocompatible probe for in vitro cellular imaging

Abstract

In this work, water-soluble highly fluorescent gold (Au) nanoclusters capped with eptifibatide (eptifibatide@Au NCs) were synthesized with sodium borohydride (NaBH4) as the reducing agent, in which sodium bromide (NaBr) was used as an excellent fluorescence sensitizer in the neutral media. The corresponding fluorescent intensity can enhance 3.37 times in comparison with that in the absence of NaBr, with the fluorescence quantum yield of 1.8%. Furthermore, the as-prepared fluorescent probe exhibits bright green fluorescence, high optical stability, excitation wavelength dependent behavior, good biocompatibility and low toxicity. Furthermore, the cell imaging experiments demonstrate that eptifibatide@Au NCs can stain the cell membrane and cytoplasm of HeLa and Chromaffin cells. These superior characteristics show their promising applications in cellular imaging and biological analysis.