Noncovalent chemical interactions, including electrostatic interactions, hydrogen bonding, and hydrophobic interactions, constitute crucial driving forces in the bottom‐up assembly of multifunctional molecular complexes and nanomaterials. Electrostatic interactions in chemical environments are generally considered as non‐specific interactions, which pose notable challenges for the control and direct measurement of electrostatic forces at the single‐molecule level. Here, we report a model system consisting of cytochrome c and molecules containing carboxyl groups, and use electrochemical AFM force spectroscopy to navigate the electrostatic forces of the system under various chemical conditions. The effects of solution pH, ion strength, and redox states of cytochrome c on electrostatic interactions as well as control over these parameters are systematically studied. This work provides a useful approach for investigating intermolecular electrostatic interactions at the single‐molecule level.

中文翻译：

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在各种化学环境中血红素蛋白与羧酸基团之间的单分子相互作用

非共价化学相互作用，包括静电相互作用，氢键和疏水相互作用，是多功能分子复合物和纳米材料自下而上组装的关键驱动力。化学环境中的静电相互作用通常被认为是非特定的相互作用，这对单分子水平上静电力的控制和直接测量提出了显着的挑战。在这里，我们报告由细胞色素c和包含羧基的分子组成的模型系统，并使用电化学原子力显微镜（AFM）力谱技术在各种化学条件下导航系统的静电力。溶液pH，离子强度和细胞色素c的氧化还原状态的影响对静电相互作用的控制以及对这些参数的控制进行了系统的研究。这项工作为研究单分子水平的分子间静电相互作用提供了一种有用的方法。