Rapid tumor bioimaging and photothermal treatment based on GSH-capped red fluorescent gold nanoclusters

Gold nanoclusters (Au NCs) possess outstanding physical and chemical attributes that make them excellent scaffolds for the construction of novel chemical sensors and biological imaging probes. In this study, a simple one-pot synthesis method, employing l -glutathione as the stabilizer, was presented for the preparation of red fluorescent Au NCs. The prepared Au NCs have no obvious cell cytotoxic effect on cancerous cells ( i.e. , HeLa, U87, and MCF-7 cells) and non-cancerous cells ( i.e. , L02 cells) in a wide concentration range. Then the prepared Au NCs were applied for tumor-targeted imaging in vitro and in vivo due to their good photo-stability, strong fluorescence emission, excellent water solubility and bio-compatibility. The observations indicate that the as-prepared Au NCs exhibited a near infrared fluorescence emission at 710 nm for in vivo bioimaging of tumors. Furthermore, Au NCs combining with porphyrin derivatives were applied for photothermal treatment to effectively inhibit the growth of tumors. This raises the possibility of utilizing Au NCs as a fluorescent probe for tumor-targeted rapid imaging and thus realize the facile fluorescence imaging-guided photothermal therapy of tumors.