A synthetic cationic surfactant, 5,5-ditetradecyl-2-(2-trimethyl-ammonioethyl)-1,3-dioxane bromide (DTDB), was used to construct a supported bilayer lipid membrane (s-BLM) coated on an underlying glassy carbon electro...A synthetic cationic surfactant, 5,5-ditetradecyl-2-(2-trimethyl-ammonioethyl)-1,3-dioxane bromide (DTDB), was used to construct a supported bilayer lipid membrane (s-BLM) coated on an underlying glassy carbon electrode (GCE). Electrochemical impedance spectroscopy (EIS), small-angle X-ray diffraction (SAXD) and cyclic voltammetry were used to characterize the s-BLM. Both EIS and SAXD data indicated that the synthetic lipid exists as a well-oriented bilayer in the membrane. The voltammetric study showed that the lipid membrane can open ion channels in the presence of C1O4- stimulant with Ru(bpy)32+ as marker ions and give distinct channel currents. The channels can be closed and open up again many times by removing or introducing ClO4- anions.展开更多
Fe3O4 particles coated with acrylic copolymer (ACP) of about 5-8 nm in diameter were synthesized and used for immobilization of horseradish peroxidase (HRP). Direct electrochemistry of HRP embedded in the nanosized Fe...Fe3O4 particles coated with acrylic copolymer (ACP) of about 5-8 nm in diameter were synthesized and used for immobilization of horseradish peroxidase (HRP). Direct electrochemistry of HRP embedded in the nanosized Fe3O4 solid matrix modified paraffin impregnated graphite electrode (PIGE) was achieved, which is related to the heme Fe(III)/Fe(II) conversion of HRP. Cyclic voltammetry gave a pah- of reproducible and well-defined redox peaks at about Em of -0.295 V vs. SCE. The standard rate constant k, was determined as 2.7 s-1. It demonstrated that the nano-Fe3O4 solid matrix offers a friendly platform to assemble the HRP protein molecules and enhance the electron transfer rate between the HRP and the electrode. UV-Vis absorption spectra and FTIR spectra studies revealed that the embedded HRP retained its native-like structure. The HRP/Fe3O4/PIGE showed a strong catalytic activity toward H2O2. The voltammetric response was a linear function of H2O2 concentration in the range of 10-140 μmol/L with detection limit of 7.3 μmol/L (s/n = 3). The apparent Michaelis-Menten constant is calculated to be 0.42 mmol/L.展开更多
基金Project supported by University of Science and Technology of China(Nos.ky1212 and ky2216).
文摘A synthetic cationic surfactant, 5,5-ditetradecyl-2-(2-trimethyl-ammonioethyl)-1,3-dioxane bromide (DTDB), was used to construct a supported bilayer lipid membrane (s-BLM) coated on an underlying glassy carbon electrode (GCE). Electrochemical impedance spectroscopy (EIS), small-angle X-ray diffraction (SAXD) and cyclic voltammetry were used to characterize the s-BLM. Both EIS and SAXD data indicated that the synthetic lipid exists as a well-oriented bilayer in the membrane. The voltammetric study showed that the lipid membrane can open ion channels in the presence of C1O4- stimulant with Ru(bpy)32+ as marker ions and give distinct channel currents. The channels can be closed and open up again many times by removing or introducing ClO4- anions.
基金Project supported by the University of Science and Technology of China(Nos.ky1212 and ky2216).
文摘Fe3O4 particles coated with acrylic copolymer (ACP) of about 5-8 nm in diameter were synthesized and used for immobilization of horseradish peroxidase (HRP). Direct electrochemistry of HRP embedded in the nanosized Fe3O4 solid matrix modified paraffin impregnated graphite electrode (PIGE) was achieved, which is related to the heme Fe(III)/Fe(II) conversion of HRP. Cyclic voltammetry gave a pah- of reproducible and well-defined redox peaks at about Em of -0.295 V vs. SCE. The standard rate constant k, was determined as 2.7 s-1. It demonstrated that the nano-Fe3O4 solid matrix offers a friendly platform to assemble the HRP protein molecules and enhance the electron transfer rate between the HRP and the electrode. UV-Vis absorption spectra and FTIR spectra studies revealed that the embedded HRP retained its native-like structure. The HRP/Fe3O4/PIGE showed a strong catalytic activity toward H2O2. The voltammetric response was a linear function of H2O2 concentration in the range of 10-140 μmol/L with detection limit of 7.3 μmol/L (s/n = 3). The apparent Michaelis-Menten constant is calculated to be 0.42 mmol/L.
