Department of Physics, Virginia Commonwealth University, Richmond, Virginia 23284, United States.
Department of Chemistry and Biochemistry, Rowan University, Glassboro, New Jersey 08028, United States.
ACS Nano. 2022 Oct 25;16(10):17229-17241. doi: 10.1021/acsnano.2c07842. Epub 2022 Oct 10.
It was recently demonstrated that one can monitor ligand-induced structure fluctuations of individual thiolate-capped gold nanoclusters using resistive-pulse nanopore sensing. The magnitude of the fluctuations scales with the size of the capping ligand, and it was later shown one can observe ligand exchange in this nanopore setup. We expand on these results by exploring the different types of current fluctuations associated with peptide ligands attaching to tiopronin-capped gold nanoclusters. We show here that the fluctuations can be used to identify the attaching peptide through either the magnitude of the peptide-induced current jumps or the onset of high-frequency current fluctuations. Importantly, the peptide attachment process requires that the peptide contains a cysteine residue. This suggests that nanopore-based monitoring of peptide attachments with thiolate-capped clusters could provide a means for selective detection of cysteine-containing peptides. Finally, we demonstrate the cluster-based protocol with various peptide mixtures to show that one can identify more than one cysteine-containing peptide in a mixture.
最近有人证明，人们可以使用电阻脉冲纳米孔传感来监测单个巯基封端的金纳米簇中配体诱导的结构波动。波动的幅度与封端配体的大小成正比，后来有人在这种纳米孔装置中观察到配体交换。我们通过探索与连接到硫普罗宁封端的金纳米簇的肽配体相关的不同类型的电流波动，扩展了这些结果。我们在这里表明，可以通过肽诱导的电流跃变的幅度或高频电流波动的开始来识别附着的肽。重要的是，肽的附着过程需要肽含有半胱氨酸残基。这表明，基于纳米孔的巯基封端簇的肽附着监测可以提供一种选择性检测含半胱氨酸肽的方法。最后，我们用各种肽混合物演示了基于簇的方案，以表明可以在混合物中识别出一种以上的含半胱氨酸肽。
