The direct electron transfer of hemoglobin at the PAMAM-MWNTs-AuNPs composite film modified glassy carbon electrode was studied. In a phosphate buffer solution（PBS, pH=7.0）, the formal potential（E^0） of Hb was -0....The direct electron transfer of hemoglobin at the PAMAM-MWNTs-AuNPs composite film modified glassy carbon electrode was studied. In a phosphate buffer solution（PBS, pH=7.0）, the formal potential（E^0） of Hb was -0.105 V versus SCE, the electron transfer rate constant was 4.66 s-1. E^0＇ of Hb at the modified electrode was linearly varied in a pH range of 5.0-8.0 with a slope of-49.2 mV/pH. The Hb/PAMAM-MWNTs-AuNPs/GCE gave an excellent electrocatalytic response to the reduction of hydrogen peroxide. The catalytic current increased linearly with H2O2 concentration in a range of 1.0× 10^-6 to 2.2× 10^-3 mol/L. The detection limit was 2.0× 10^-7 mol/L at a signal to noise ratio of 3. The Michaelis-Menten constant（Km^app） was 2.95 mmol/L.展开更多
Composite membranes based on sulfonated silica/sulfonated poly（ether ether ketone）（SPEEK） were prepared by means of sol-gel method so as to gain a high conductivity and reasonable methanol permeability.The sulfona...Composite membranes based on sulfonated silica/sulfonated poly（ether ether ketone）（SPEEK） were prepared by means of sol-gel method so as to gain a high conductivity and reasonable methanol permeability.The sulfonated silica is generated in situ via the hydrolysis of sulfonated 3-anminopropyl triethoxysilane（KH550） synthesized newly from 3-aminopropyl triethoxysilane and 1,4-butane sultone.The membrane with a silica mass fraction of 5% exhibits a conductivity of 0.187 S/cm at 80 °C and a methanol coefficient with 9.72×10-7 cm2/s.The composite membranes show improved condutive ability and better selectivity that can be promisingly used in direct methanol fuel cell.展开更多
Sericin（SS）, as an abtmdant and renewable resource in nature, has been proven to be a good adsorbent for metal ions or organic dyes removal. In this study, glutaraldehyde vapor cross-linked sericin-based electrospun...Sericin（SS）, as an abtmdant and renewable resource in nature, has been proven to be a good adsorbent for metal ions or organic dyes removal. In this study, glutaraldehyde vapor cross-linked sericin-based electrospun fiber adsorbent was developed for the removal of methylene blue（MB） from wastewater. To overcome the problem of decreasing adsorption capacity by excessive functional group cross-linking, MB-imprinted sericin/poly（vinyl alcohol） （PVA） electrospun fiber adsorbent was prepared. Biocompatible PVA was added to the electrospinning solution to improve the spinnability and mechanical property. Scanning electron microscopy（SEM）, Fourier transforms infrared spectroscopy（FTlR）, and so forth were used to confirm their structures and composition. The adsorption performance toward the template molecule MB, including pH effect, adsorption isotherm, adsorption kinetics, adsorption selectivity, and reusability, was investigated. By comparison with non-imprinted sericin/PVA electrospun fibers, MB-imprinted sericin/PVA electrospun fiber adsorbent showed an enhanced and selective adsorption capacity toward MB with a good regeneration and recycling ability. The adsorption test suggests that the resulting MB-imprinted sericin/PVA electrospun fibers are promising adsorbents for MB removal from aqueous system.展开更多
基金Supported by the National Natural Science Foundation of China(No.20605009)
文摘The direct electron transfer of hemoglobin at the PAMAM-MWNTs-AuNPs composite film modified glassy carbon electrode was studied. In a phosphate buffer solution（PBS, pH=7.0）, the formal potential（E^0） of Hb was -0.105 V versus SCE, the electron transfer rate constant was 4.66 s-1. E^0＇ of Hb at the modified electrode was linearly varied in a pH range of 5.0-8.0 with a slope of-49.2 mV/pH. The Hb/PAMAM-MWNTs-AuNPs/GCE gave an excellent electrocatalytic response to the reduction of hydrogen peroxide. The catalytic current increased linearly with H2O2 concentration in a range of 1.0× 10^-6 to 2.2× 10^-3 mol/L. The detection limit was 2.0× 10^-7 mol/L at a signal to noise ratio of 3. The Michaelis-Menten constant（Km^app） was 2.95 mmol/L.
基金Supported by the National High-Tech Research and Development Program of China(No.2007AA03Z218)
文摘Composite membranes based on sulfonated silica/sulfonated poly（ether ether ketone）（SPEEK） were prepared by means of sol-gel method so as to gain a high conductivity and reasonable methanol permeability.The sulfonated silica is generated in situ via the hydrolysis of sulfonated 3-anminopropyl triethoxysilane（KH550） synthesized newly from 3-aminopropyl triethoxysilane and 1,4-butane sultone.The membrane with a silica mass fraction of 5% exhibits a conductivity of 0.187 S/cm at 80 °C and a methanol coefficient with 9.72×10-7 cm2/s.The composite membranes show improved condutive ability and better selectivity that can be promisingly used in direct methanol fuel cell.
基金Supported by the National Natural Science Foundation of China（Nos. 51173082, 21474043）.
文摘Sericin（SS）, as an abtmdant and renewable resource in nature, has been proven to be a good adsorbent for metal ions or organic dyes removal. In this study, glutaraldehyde vapor cross-linked sericin-based electrospun fiber adsorbent was developed for the removal of methylene blue（MB） from wastewater. To overcome the problem of decreasing adsorption capacity by excessive functional group cross-linking, MB-imprinted sericin/poly（vinyl alcohol） （PVA） electrospun fiber adsorbent was prepared. Biocompatible PVA was added to the electrospinning solution to improve the spinnability and mechanical property. Scanning electron microscopy（SEM）, Fourier transforms infrared spectroscopy（FTlR）, and so forth were used to confirm their structures and composition. The adsorption performance toward the template molecule MB, including pH effect, adsorption isotherm, adsorption kinetics, adsorption selectivity, and reusability, was investigated. By comparison with non-imprinted sericin/PVA electrospun fibers, MB-imprinted sericin/PVA electrospun fiber adsorbent showed an enhanced and selective adsorption capacity toward MB with a good regeneration and recycling ability. The adsorption test suggests that the resulting MB-imprinted sericin/PVA electrospun fibers are promising adsorbents for MB removal from aqueous system.
