加拿大女王大学Cathleen M. Crudden研究团队报道了配体结构对NHC保护的Au₁₃纳米簇生物活性和光物理性质的影响。相关研究成果于2025年1月22日发表在国际顶尖学术期刊《美国化学会杂志》。

N-杂环卡宾（NHC）保护的金纳米簇具有高稳定性和高光致发光性，使其非常适合荧光成像和光动力治疗应用。

该文中，研究人员报道了两种具有π扩展芳香体系的双NHC保护的Au₁₃纳米簇的合成。根据π扩展芳香体系的位置，观察到簇中配体壳结构的变化，并能够将刚性的增加与荧光量子产率的增加相关联。密度泛函理论分析表明，两种合成的Au₁₃纳米簇都是8电子超原子，但在最低未占单电子态的特征上存在明显差异。

从定性上讲，这意味着在基本能隙上激发和衰减的机制不同。研究人员进行了稳定性和光物理研究，以获得两个团簇的发射寿命和光学纯度。在体外使用共聚焦显微镜在人上皮癌细胞中证实了纳米簇的主动细胞内摄取。测得活性氧物种的产生效率为7%。癌症细胞中的高团簇稳定性、光致发光量子产率和有效的细胞摄取表明，这些纳米团簇具有作为高效和可调纳米医疗平台的潜力。

附：英文原文

Title: Impact of Ligand Structure on Biological Activity and Photophysical Properties of NHC-Protected Au13 Nanoclusters

Author: Viveka K. Kulkarni, Emily L. Albright, Elham Zeinizade, Emily Steele, Juan Chen, Lili Ding, Sami Malola, Shinjiro Takano, Kristen Harrington, Nahyun Kwon, Tetyana I. Levchenko, Masakazu Nambo, Tatsuya Tsukuda, Hannu Hkkinen, Kevin Stamplecoskie, Gang Zheng, Cathleen M. Crudden

Issue&Volume: January 22, 2025

Abstract: N-heterocyclic carbene (NHC)-protected gold nanoclusters display high stability and high photoluminescence, making them well-suited for fluorescence imaging and photodynamic therapeutic applications. We report herein the synthesis of two bisNHC-protected Au13 nanoclusters with π-extended aromatic systems. Depending on the position of the π-extended aromatic system, changes to the structure of the ligand shell in the cluster are observed, with the ability to correlate increases in rigidity with increases in fluorescence quantum yield. Density functional theory analysis reveals that both synthesized Au13 nanoclusters are 8-electron superatoms but have distinct differences in the characteristics of the lowest unoccupied single-electron states. Qualitatively, this implies different mechanisms for excitations and their decay over the fundamental energy gap. Stability and photophysical studies were carried out to provide the emission lifetime and optical purity of the two clusters. Active intracellular uptake of the nanoclusters was confirmed in vitro using confocal microscopy in human epithelial carcinoma cells. Reactive oxygen species production was measured at 7% efficiency. The high cluster stability, photoluminescence quantum yields, and efficient cellular uptake in cancer cells suggest potential for these nanoclusters as highly efficient and tunable nanomedical platforms.

DOI: 10.1021/jacs.4c12072

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.4c12072