Ma Qun, Liu Lichao, Yang Zeyue, Zheng Peng
Chemistry and Biomedicine Innovation Center (ChemBIC), State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, 163 Xianlin Road, Nanjing 210023, China.
Nanomaterials (Basel). 2021 Nov 2;11(11):2932. doi: 10.3390/nano11112932.
The synthesis of ultra-small gold nanoclusters (Au NCs) with sizes down to 2 nm has received increasing interest due to their unique optical and electronic properties. Like many peptide-coated gold nanospheres synthesized before, modified gold nanoclusters with peptide conjugation are potentially significant in biomedical and catalytic fields. Here, we explore whether such small-sized gold nanoclusters can be conjugated with peptides also and characterize them using atomic force microscopy. Using a long and flexible elastin-like polypeptide (ELP) as the conjugated peptide, (ELP)-Au NCs was successfully synthesized via a one-pot synthesis method. The unique optical and electronic properties of gold nanoclusters are still preserved, while a much larger size was obtained as expected due to the peptide conjugation. In addition, a short and rigid peptide (EAAAK) was conjugated to the gold nanoclusters. Their Yong's modulus was characterized using atomic force microscopy (AFM). Moreover, the coated peptide on the nanoclusters was pulled using AFM-based single molecule-force spectroscopy (SMFS), showing expected properties as one of the first force spectroscopy experiments on peptide-coated nanoclusters. Our results pave the way for further modification of nanoclusters based on the conjugated peptides and show a new method to characterize these materials using AFM-SMFS.
尺寸低至2纳米的超小金纳米团簇（Au NCs）的合成因其独特的光学和电子性质而受到越来越多的关注。与之前合成的许多肽包被金纳米球一样，通过肽缀合修饰的金纳米团簇在生物医学和催化领域具有潜在的重要意义。在这里，我们探究如此小尺寸的金纳米团簇是否也能与肽缀合，并使用原子力显微镜对其进行表征。使用一种长且具柔性的类弹性蛋白多肽（ELP）作为缀合肽，通过一锅合成法成功合成了（ELP）-Au NCs。金纳米团簇独特的光学和电子性质仍然得以保留，同时由于肽缀合，如预期那样获得了大得多的尺寸。此外，一种短且刚性的肽（EAAAK）被缀合到金纳米团簇上。使用原子力显微镜（AFM）对它们的杨氏模量进行了表征。此外，利用基于AFM的单分子力谱（SMFS）对纳米团簇上包被的肽进行了拉伸，作为对肽包被纳米团簇的首批力谱实验之一，显示出预期的性质。我们的结果为基于缀合肽对纳米团簇进行进一步修饰铺平了道路，并展示了一种使用AFM-SMFS表征这些材料的新方法。
