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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 ex-cellent electrocatalytic response to the reduction of hydrogen peroxide. The catalytic current increased linearly with H 2 O 2 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(K ma pp ) was 2.95 mmol/L.
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- Au NPs / GCE gave an ex-cellent electrocatalytic response to the reduction of hydrogen peroxide. The catalytic current increased linearly with H 2 O 2 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 (K ma pp) was 2.95 mmol / L.