Ligand Engineering of Gold Nanoclusters for NIR-II Imaging

作者：Meili Guo, Gang Zhang, Ruoli Zhao, Huizhen Ma, Yuxing Yan, Shuyu Yang, Jian Meng, You Huang, Xiaodong Zhang, Hao Wang, Ruiping Zhang · 发表于：ACS Applied Nano Materials · 年份：2023 · DOI：10.1021/acsanm.3c02888 · 被引用次数：46 · 研究领域：Nanocluster Synthesis and Applications、Advanced Nanomaterials in Catalysis、Carbon and Quantum Dots Applications

Near-infrared-II (NIR-II) imaging has shown great potential in medical diagnosis and surgical navigation, but developing safe, photostable, high-brightness molecular probes remains a great challenge. Due to their ultrasmall size resulting in highly efficient renal clearance, gold nanoclusters have shown great clinical potential. In this work, we systematically explored the effect of different ligands on the luminescence and bioactivity of gold nanoclusters. Our results show that gold nanoclusters protected by thioglycolic acid (TGA) and 6-mercaptohexanoic acid (MHA) exhibit the strongest fluorescence, while 3-mercaptopropionic acid (MPA)- and sodium sulfide (Na 2 S)-protected gold nanoclusters show the weakest NIR-II signal. Further doping showed that the Cd-doped MPA and MHA-protected gold nanoclusters exhibited enhanced fluorescence, but the cysteine (Cys)-, glutathione (GSH)-, and Na 2 S-protected gold nanoclusters showed fluorescence quenching after doping, indicating significant ligand selectivity. Because of the unique multi-energy structure and the large number of electronic states at the highest occupied molecular orbital energy level, MPA- and MHA-protected gold nanoclusters exhibit high stability and photostability. In addition, gold nanoclusters with different ligands exhibited different selective enzyme-mimicking activities of peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT). Imaging in vivo showed that gold nanoclusters could accomplish reliable i...