Peptide-directed green synthesis of gold nanoclusters with deep red fluorescence for long-term bioimaging of nucleus

Abstract

Fluorescent imaging probes for the visualization of nuclear structure and function in live cells play a fundamentally crucial role in exploring major cellular events. In this study, we report a novel fluorescent nanoprobe, nucleus targeted peptide stabilized gold nanoclusters (NTP-Au NCs) with fluorescence emission of a long wavelength (671 nm), high fluorescence quantum yield (6.8%) and excellent photostability for long-term nucleus targeted imaging. Our nanoprobe is synthesized through a facile one-pot method by utilizing a heptapeptide (CCYETWW) as the stabilizing ligand. The heptapeptide was designed with two bifunctional segments, with segment 1 (CCY) as the stabilized agent for the synthesis of Au NCs and segment 2 (ETWW) for nucleus targeting. Further investigations demonstrated that the NTP-Au NCs exhibited remarkable photostability, low cytotoxicity, and an excellent nucleus-targeting capability. Owning to these appealing merits, the application of NTP-Au NCs for the long-term tracking of the nucleus inside live cells achieved great success.