The Prepare Of Selenocystine Self-assembly Monolayers Modified Electrodes And It's Application In Study On Electrochemistry Reaction Of Cytochrome C

It is one of the trends of chemistry to use electrochemical methods in studying biological phenomena. Applications of self-assemble monolayers(SAMs) and surfactants have made great progress in modified electrodes and electrochemistry study of biologic molecular. So this thesis studied mainly on the characteristic of Selenocystine (SeCys) SAMs and its application in the electrochemical study of cytochrome c. The details are as follows:The properties of SeCys SAMs on gold were investigated by cyclic voltammetry and impedance measurements with Fe(CN)₆^3- as a probe. The results indicated that the SeCys SAMs can hinder the electron-transfer reaction of Fe(CN)₆^3-. The acidity of the K₃Fe(CN)₆ solution have effect on electron-transfer reaction of Fe(CN)₆^3- on SeCys/Au electrode: acidic solution can improve the electron-transfer reaction of Fe(CN)₆^3-, while basic solution not only hinder the electron-transfer reaction of Fe(CN)₆^3-,but also destroy the SeCys SAMs. It was found that surfactants show some effects on the electron-transfer reaction at the SeCys modified gold electrode: cationic surfactants can improve the reversibility of a redox reaction, while anionic surfactants cause inhibition of electron-transfer of redox. The adsorb pattern between SeCys SAMs and cetyltrimethylammonium bromide(CTAB) was investigated by electrochemical and connect angle experiments.It was proved that SeCys could accelerate the redox reaction of Cyt c on electrode in our study. Compared with SeCys, the accelerating effect of CTAB-SeCys is stronger , and the redox process is controlled by diffusion. The accelerating effect of SeCys was also proved by spectrum experiments. The effect of ionic strength of buffer solution on the redox reaction of Cyt c was evaluated. The results showed that the ionic strength of buffer solution had little to do with the redox reaction of Cyt c in the range of 0.03-0.30 mol/L. Also, the effect of the concentration of CTAB on the redox reaction of Cyt c was evaluated. It was found that the currents of redox reaction was increased with the concentration o f CTAB, and a maximum was appeared when the concentration is near the cmc of CTAB.