Rapid synthesis of highly luminescent and stable Au sub(20) nanoclusters for active tumor-targeted imaging in vitroand in vivo

• Published in: Nanoscale Vol. 6; no. 4; pp. 2261 - 2269
• Main Authors: Zhang, Pu, Yang, Xiao Xi, Wang, Yi, Zhao, Ning Wei, Xiong, Zu Hong, Huang, Cheng Zhi
• Format: Journal Article
• Language: English
• Published: 01.01.2014
• Subjects: Biomedical materials; Fluorescence; Imaging; In vivo testing; In vivo tests; Nanostructure; Surgical implants; Synthesis
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/c3nr05269a

Rapid synthesis of protein-stabilized Au sub(20) nanoclusters (Au sub(20)NCs) with high fluorescence quantum yield (QY) up to similar to 15% is successfully achieved by manipulating the reaction kinetics. The as-obtained Au sub(20)NCs, identified by mass spectrometry, have an average size of 2.6 nm, with strong fluorescence emission at 620 nm (2.00 eV) upon excitation at either 370 nm (3.35 eV) or 470 nm (2.64 eV). The advantages of the as-obtained Au sub(20)NCs, including small sizes, high fluorescence QY, excellent photostability, non-toxicity, and good stability in biological media, make them ideal candidates as good luminescent probes for optical imaging in vitroand in vivo. Our results demonstrate that the uptake of Au sub(20)NCs by both cancer cells and tumor-bearing nude mice can be improved by receptor-mediated internalization, compared with that by passive targeting. Because of their selective accumulation at the tumor sites, the Au sub(20)NC probes can be used as potential indicators for cancer diagnosis. This work not only provides a new understanding of the rapid synthesis of highly luminescent Au sub(20)NCs but also demonstrates that the functionalized-Au sub(20)NCs are excellent probes for active tumor-targeted imaging in vitroand in vivo.