The vesicle of didodecyldimethylammonium bromide (DDAB) which containedtetrathiafulvalene (TTF) was mixed with xanthine oxidase, and the mixture was cast on the pyrolyticgraphite electrode. The lipid films were used t...The vesicle of didodecyldimethylammonium bromide (DDAB) which containedtetrathiafulvalene (TTF) was mixed with xanthine oxidase, and the mixture was cast on the pyrolyticgraphite electrode. The lipid films were used to supply a biological environment resemblingbiomembrane on the surface of the electrode. TTF was used as a mediator because of its highelectron-transfer efficiency. A novel xanthine biosensor based on cast DDAB film was developed. Theeffects of pH and operating potential were explored for optimum analytical performance by using theamperometric method. The response time of the biosensor was less than 10 s. The detection limit ofthe biosensor was 3.2 x 10^(-7) mol/L and the liner range was from 4 x 10^(-7) mol/L to 2.4 x10^(-6) mol/L.展开更多
The ferrocene-lipid film electrode was successfully prepared by means ofcasting the solution of ferrocene and lipid in chloroform onto a glassy carbon (GC) electrodesurface. Ferrocene saved in the biological membrane ...The ferrocene-lipid film electrode was successfully prepared by means ofcasting the solution of ferrocene and lipid in chloroform onto a glassy carbon (GC) electrodesurface. Ferrocene saved in the biological membrane gave a couple of quasi-reversible peaks ofcyclic voltammogram. The electrode displays a preferential electrocatalytic oxidation of dopamine(DA). The effect of electrocatalytic oxidation of DA depends on the solution pH and the negativecharge lipid is in favor of catalytic oxidation of DA. The characteristic was employed forseparating the electrochemical responses of DA and ascorbic acid (AA). The electrode was assessedfor the voltammetric differentiation of DA and AA. The measurement of DA can be achieved withdifferential pulse voltammetry in the presence of high concentration of AA. The catalytic peakcurrent was proportional to the concentration of DA in the range of 1 x 10^(-4)―3x10^(-3) mol/L.展开更多
The structure and the electron-transfer of cytochrome c binding on the anionic lipid vesicles were analyzed by electrochemical and various spectroscopic methods. It was found that upon binding to anionic lipid membran...The structure and the electron-transfer of cytochrome c binding on the anionic lipid vesicles were analyzed by electrochemical and various spectroscopic methods. It was found that upon binding to anionic lipid membrane, the formal potential of. cytochrome c shifted 30 mV negatively indicating an eager redox interaction than that in its native state. This is due to the local alteration of the coordination and the heme crevice. The structural Perturbation in which a molten globule-like state is formed during binding to anionic lipid vesicles is more important. This study may help to understand the mechanism of the electron-transfer reactions of cytochrome c at the mitochondrial membrane.展开更多
文摘The vesicle of didodecyldimethylammonium bromide (DDAB) which containedtetrathiafulvalene (TTF) was mixed with xanthine oxidase, and the mixture was cast on the pyrolyticgraphite electrode. The lipid films were used to supply a biological environment resemblingbiomembrane on the surface of the electrode. TTF was used as a mediator because of its highelectron-transfer efficiency. A novel xanthine biosensor based on cast DDAB film was developed. Theeffects of pH and operating potential were explored for optimum analytical performance by using theamperometric method. The response time of the biosensor was less than 10 s. The detection limit ofthe biosensor was 3.2 x 10^(-7) mol/L and the liner range was from 4 x 10^(-7) mol/L to 2.4 x10^(-6) mol/L.
文摘The ferrocene-lipid film electrode was successfully prepared by means ofcasting the solution of ferrocene and lipid in chloroform onto a glassy carbon (GC) electrodesurface. Ferrocene saved in the biological membrane gave a couple of quasi-reversible peaks ofcyclic voltammogram. The electrode displays a preferential electrocatalytic oxidation of dopamine(DA). The effect of electrocatalytic oxidation of DA depends on the solution pH and the negativecharge lipid is in favor of catalytic oxidation of DA. The characteristic was employed forseparating the electrochemical responses of DA and ascorbic acid (AA). The electrode was assessedfor the voltammetric differentiation of DA and AA. The measurement of DA can be achieved withdifferential pulse voltammetry in the presence of high concentration of AA. The catalytic peakcurrent was proportional to the concentration of DA in the range of 1 x 10^(-4)―3x10^(-3) mol/L.
基金ProjectsupportedbytheNationalNaturalScienceFoundationofChina (No .2 983 5 12 0 )
文摘The structure and the electron-transfer of cytochrome c binding on the anionic lipid vesicles were analyzed by electrochemical and various spectroscopic methods. It was found that upon binding to anionic lipid membrane, the formal potential of. cytochrome c shifted 30 mV negatively indicating an eager redox interaction than that in its native state. This is due to the local alteration of the coordination and the heme crevice. The structural Perturbation in which a molten globule-like state is formed during binding to anionic lipid vesicles is more important. This study may help to understand the mechanism of the electron-transfer reactions of cytochrome c at the mitochondrial membrane.
