Study On Electrochemical Biosensors Based On Chiral Amino Acids

Chiral recognition, the basic of life, is a special recognition process in natural. In recent years, as the development of materials science, electronic technology and the advances in detection methods, it is gradually being a new way which not only help us to find out the operation mechanism of organisms and some important life processes, but also own significant value in analysis, novel nano-material preparation, drug discovery, pharmacological research and so on. In this paper, chiral amino acids or chiral nano-compounds were utilized to fabricate amperometric biosensors, to investigate the chiral recognition between amino acids and the bio-macromolecule. The dissertation describled as follows:1.An interesting phenomenon of the stereoselective interaction between biological macromolecule and amino acid enantiomorphous was described. Firstly, proline enantiomer (L-and D-proline) was assembled on the glassy carbon electrode surface. Then carcinoembryonic antibody (anti-CEA) was loaded to the enantiomer surface, electro-chemical impedance spectroscopy (EIS) was used to monitor the growth of amino acid film. The assembly process was characterized by cyclic voltammetry (CV) and atomic force microscopy (AFM) was applied to image the chiral films. Finally, the developed electrodes had interacted with carcinoembryonic antigen (CEA) in varying concentration solutions. The AFM and amperometric results revealed that the proline enantioner had the chiral recognition functionto antibody.2. Electrochemical immunoassay was used to study the chiral nanocomposites (CAMs) in recognition of prostate-specific antibody (PSA), which were formed by L-and D-arginine (Arg) and multi-walled carbon nanotubes (MWNTs). The chiral nanocomposites and the modified electrode processes were analyzed by photochemical and electrochemical means. Nano-gold and Prussian Blue applied for signal amplification were introduced. CAMs have performance of chiral recognition with good electrical capability and chemical stability.3.Different nano-materials were employed to build three kinds of hydrogen peroxide biosensors, respectively. The mixture was made by horseradish peroxidase (HRP), chitosan (CS) and nanotubes (L-, DAMs or MWNTs), and modified on the glassy carbon electrodes. A comparative study of three kinds of hydrogen peroxide biosensors modified by different nanotubes was investigated by electrochemical technique, and the chiral recognition of CAM to HRP was analysed.