Gugała-Fekner Dorota
Faculty of Chemistry, Maria Curie-Sklodowska University, Lublin, Poland.
Monatsh Chem. 2018;149(8):1357-1365. doi: 10.1007/s00706-018-2183-1. Epub 2018 Jun 28.
The measurements of double-layer differential capacitance, zero charge potential, and surface tension at that potential allowed us to examine the adsorption properties of adenine on the mercury surface from the neat buffer solution, i.e., the acetate buffer at pH 5 and pH 6. The systems obtained at such pH values were close to physiological fluids in their characteristics. The adsorption energy and interaction constants were determined using Frumkin isotherm and virial isotherm. It was shown that the adenine molecule is adsorbed on the mercury electrode with its negative pole against the electrode surface. Using the cyclic voltammetry technique and measuring Faraday impedance, an increasing effect of adenine on the kinetics of zinc ion electroreduction was found. In both buffer solutions, the neutral adenine molecules can form on the surface of the working electrode, an unstable active complex with depolarizer ions, facilitating electron exchange.
通过测量双层微分电容、零电荷电位以及该电位下的表面张力，我们得以研究腺嘌呤在纯缓冲溶液（即pH值为5和6的醋酸盐缓冲溶液）中在汞表面的吸附特性。在这些pH值下得到的体系在特性上接近生理流体。使用弗鲁姆金等温线和维里等温线确定了吸附能和相互作用常数。结果表明，腺嘌呤分子以其负极朝向电极表面的方式吸附在汞电极上。利用循环伏安法技术并测量法拉第阻抗，发现腺嘌呤对锌离子电还原动力学有增强作用。在两种缓冲溶液中，中性腺嘌呤分子可在工作电极表面与去极化剂离子形成不稳定的活性络合物，促进电子交换。
