Stereoselective Recognition Of Chiral Electroactive Molecules By Electrocatalysis

Chiral material (including chiral medicine and chiral molecule) has the important research value in the fileds of life science, drug science, medicine and superfine chemical industry, so chiral recognition techniques are developing to the low cost and rapid detection.And the electrochemistry has the advantages of high sensitiveness, rapid and low detection, that provide the special research background and scientific value to chiral recognition. This paper is to explore electron transfer on the chiral surface and investigate stereoselective recognition between chiral surfaces and chiral electroactive molecules, and research jobs are as follows:1. Electrochemical reduction of tyrosine (Tyr) enantiomers on gold matrices in chlorhydric acid (HCl) solutions (0.01 M, pH 2.00) was performed. The characteristics of the Tyr reductive product adsorbed onto the electrode surface were studied using cycle voltammetry (CV). The compared investigation about electrocatalytic ability of Tyr enantiomers used gold matrices (bare gold electrode and electrodepositive gold nanoparticles modified glassy carbon electrode (AuNPs-GCE)). The scanning electron microscope (SEM) images have been utilized to discuss the surface morphous. And the redox degree of L-Tyr on gold matrices was obviously much larger than that of D-Tyr. The mechanism for stereoselectivity in redox reactions of Tyr enantiomers on gold matrices had been analyzed. In addition, the AuNPs-GCE was used to determine Tyr enantiomers. This method proposed the possibility of using a nanostructured surface to discriminate and determine the chiral molecules in bio-electroanalytical application.2. We reported the enantioselective redox reactions of ascorbic acid (L-AA) and isoascorbic acid (D-AA) on the chiral electropolymerized film constructed by L-or D-glutamic acid. The atomic force microscopy (AFM) images of L- and D-glutamic acid (Glu) electropolymerized films have been investigated. The experiments exhibited that both L- and D-Glu electropolymerized films could be used to discriminate L-AA and D-AA. However, compared with electrocatalytic and discriminating responses to L-AA and D-AA, D-Glu electropolymerized film was obviously more effective than L-Glu electropolymerized film, and the Gibbs energy of iron transfer was calculated to further confirm the phenomenon. Otherwise,under the optimized conditions, D-Glu electropolymerized film was used to determine L-AAand D-AA. This simple method could be used not only to discriminate L-AA and D-AA, but also quantitatively analyze L-AA and D-AA.3.This work used the L-methotrexate (L-Mtx) polymer film to discriminate D/ L-dioxyphenylalanine (DOPA), D/ L-AA, and D/ L-Tyrosine (Tyr). Scanning electron microscopy studied the morphology of L-Mtx polymer film. And polymer films were used to electrocatalyze the three pairs of chiral electroactive molecules by differential pulse electrochemical. The results exhibited that the chiral polymer film showed stronger electrocatalytic ability of L-configuration than that of D-configuration (three pairs of chiral molecules are the same condition).And After analysis of molecular structure, we have disucussed the different electro-catalytic behavior reasons for chiral electroactive molecules and explained the stereoselective recognition mechanism.