Exploring the in-situ conversion of intermolecular hydrogen bonds into static electricity through experimental and theoretical methods

In order to deeply understand the mechanism of biological function, it is significance to study conversion of weak interactions at the biomembrane surface. In this paper, the 3-mercaptopropionic acid self-assembled monolayer (3-MPA SAM) was constructed as a simplified model to simulate biomembrane, in which ferrocene carboxylic acid (FcCOOH) is adsorbed on the membrane surface through hydrogen bonds. Under positive potential induction, the in-situ conversion of hydrogen bonds into static electricity was investigated using scanning electrochemical microscopy (SECM). The conversion mechanism was the positive potential promoting the dissociation of carboxylic acids (COO − ) on the membrane surface, followed by electrostatic attraction with the oxidation products (Fc + COOH). The study also found a positive correlation between conversion rate and potential value. Based on density functional theory (DFT), relevant information such as molecular structure, electrostatic potential and binding energy were obtained, and key sites of weak interactions were visualized using a reduced density gradient (RDG). The universality and competitiveness of conversion have been confirmed in different environments. This work provided some reference for revealing the properties and variations of weak interaction conversion at the biomembrane surface.