Electrochemical Process Of Lysine And DMPC Biomimetic Membrane

The adsorption and oxidation of lysine on Au electrodes in alkaline solutions, and the electrochemical behavior of p-dihydroxybenzene in DMPC biomimetic membrane were studied using cyclic voltammetry(CV),in situ FTIR spectroscopy(in situ FTIRS),electrochemical quartz crystal microbalance(EQCM) and electrochemical surface plasmon resonance(EC-SPR).The main results are listed below.1.We have developed a new and alternative approach for preparing SPR active gold substrates.Our strategy is based on self-assembly of gold colloid monolayer and followed by electroless gold plating.The method affords facile control of both the thickness and the surface roughness of the resulting gold films on the nanometer scale, and the as-prepared substrates are more suitable for electrochemical studies.2.The dissociative adsorption of lysine on Au surface can occur in low potential region,and the chemisorbed species were identified as adsorbed CN^- species.Another reversibly adsorbed species may be the deprotonated amino acid,which were bound to the surface by both oxygen atoms of carboxyl group.The CN_ad^- species which derived from -CH_xNH₂ group are stable on Au electrodes in the potential region from -0.8 to 0.0 V,and can be oxidized to NCO^-,cyanate(OCN^-),and gold cyanide (AuCN)species.Concomitantly,lysine was also oxidized to CO₂ and CO₃^2-.It has developed the knowledge concerning the reaction mechanism of amino acids.3.We have used the casting method to form DMPC mimetic biomembrane on an Au electrode.The electrochemical behavior of p-dihydroxybenzene in this membrane was investigated.The orientation of the DMPC molecules could be changed with increasing electrode potential.P-dihydroxybenzene can reach the electrode surface and occur redox reactions by passing through the ion channels of biomembrane.This reaction occur in the bionic environment,which provide the useful help to study the real reaction of small molecules in the biological organisms.The results obtained in this thesis have thrown a light on elucidating the interaction mechanism of amino acid molecules with Au surfaces at molecule level. The current studies are also of importance in electrocatalysis,medication and bio-sensors applications.P-dihydroxybenzene is biologically important molecule because of its function of transferring electrons in lipid layers.Studies on the electrochemical behavior of p-dihydroxybenzene in the DMPC biomimetic membrane provide useful information for elucidating biological electron transfer processes concerning lipid layers.