Ferrocene - Glutathione Synthesis And Electrochemical Applications

The interactions and molecule recognitions between heavy metals andpeptides, small molecules and proteins are of great importance because oftheir physiological significance. In this dissertation, a series of novelferrocene-peptide derivatives were designed and synthesized for detectionof heavy metal ions and the interactions between small molecular andprotein by electrochemical method were investigated as well.Several ferrocenyl derivates, such as 1'-cysteaminecarbonyl-1-methoxycarbonyl-ferrocene (yield 30.0%), 1'-cysteaminecarbonyl-1-ferrocenlycarboxylic acid (90.0%), ferrocenoyl-amino (98.2%) andglutathione-ferrocenoyl (90.7%) were synthesized and characterized fromferrocene, while HBTU and EDC/NHS as coupling agents. The structuresof these compounds were taken to characterize with IR spectrum, UV-visspectrum and ¹H NMR. Reasonable synthetic route was suggested andsome reactions were improved.In this paper, the gold electrodes were modified byferrocenoyl-derivatives and 11-mercaptoundecanoic acid (MUA) in director indirect self-assembly methods and characterized by electrochemicalmethod. The electrochemical characterize of these ferrocenoyl-peptideswere carred out by cyclic voltammogram. The electrochemicalexperimental results showed thatr all ferrocene compounds wereexhibited one electron oxidative reaction that attributed to ferrocene'soxidative reaction. And different ferrocenoyl-peptides have distinct redoxpeaks. The redox peak potential of 1'-cysteaminecarbonyl- 1-ferrocenlycarboxylic acid, 1'-cysteaminecarbonyl-1- glutathione-carbonyl ferrocene, MUA-ferrocenoyl-amine and MUA-glutathione-ferrocenoyl modified electrodes as follow: E_pa=0.642 V, E_pc=0.740 V,E_pa=0.645 V, E_pc=0.748 V, E_pa=-0.009 V, E_pc=-0.145 V, E_pa=0.257 V,E_pc=0.132 V, respectively.Glutathione (GSH), which has eight potential binding sites to cooperatewith heavy metals, is a most favorable oligopeptide has been investigated.In this paper, 1'-cysteaminecarbonyl-1-glutathionecarbonylferrocenoylwas used to modify the gold electrode which used as a probe to detect cadmium ions. The electrochemical results showed that after accumulateCd²⁺ (20 nmol/L) on the surface of the electrod, the redox peak potentialof 1'-cysteaminecarbonyl-1-glutathionecarbonyl ferrocene modifiedelectrode was E_pa=0.820 V, E_pc=0.780 V respectively. It was caused 80m V anodic shift compared with the modified electrode which none Cd²⁺accumulate. Furthermore, the shifts are proportion to the concentration ofions in the solution when the concentration of Cd²⁺ is lower than 20nmol·L^-1. So the CSA-Fc-GSH modified electrode was used to detectedcadmium ions at low concentration and got the detection limitation ofCd²⁺ 0.1 nmol·L^-1.In this work, the interactions between glutathione and bovine serumalbumin (BSA) were studied in detail by electrochemical method for thefirst time. The results shows that the redox peak potential ofMUA-BSA-GSH-Fc modified electrode was E_pa=0.262 V and E_pc=0.159V, which shift to anodic compared to MUA-GSH-Fc modified electrode.Further more, the UV adsorb band of the BSA and GSH mixture shift tored position. It confirms that there are special interaction between BSAand GSH. It is possible that these two molecular have formedinter-molecular hydrogen bond and salt linkage. But it is uncertain whichone it is from the electrochemical result. It needs a further study tounderstand the detail interaction and the binding constant.