The electrochemical behavior of L-histidine in various aqueous media has been investigated. The systems investigated were a pH  11 phosphate buffer, as well as a pH 7.4 phoshpate buffer and a pH 7.4 MOPS buffer. In the two phosphate buffers, square wave voltammetric (SWV) results showed that L-histidine undergoes oxidation near the positive background potential limit.  The effect of zinc(II) additions to L-histidine solutions was also investigated. It was found that any zinc(II) phosphate precipate would dissolve upon addition of L-histidine, due to the complexing of the zinc(II) ion by L-histidine. The most significant findings were discovered using the pH 7.4 MOPS buffer, which does not form a complex with zinc(II) ion. The zinc(II) concentration was kept below 2 mM, however, in order to prevent any precipitation of zinc(II) hydroxide. In these experiments, it was found that when there was a 1:2 molar ratio of zinc(II) to L-histidine there was a negative potential shift of nearly 100 mV in both cyclic voltammetric and square wave voltammetric experiments. The majority of the experiments have been conducted at glassy carbon, as well as some work with gold and platinum electrodes, as a means of comparing L-histidine electrochemistry under different electrochemical conditions.

Electrochemical studies of L-histidine/zinc interactions in aqueous media

255th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.