| 17569598 |
Shan D, Wang S, Zhu D, Xue H: Studies on direct electron transfer and biocatalytic properties of hemoglobin in polyacrylonitrile matrix. Toxicol Lett. 2002 Jun 24;132(3):197-219.
The direct electrochemistry of hemoglobin (Hb) immobilized in polyacrylonitrile (PAN) modified glassy carbon electrode was described. The protein-PAN film exhibited a pair of well-defined and quasi-reversible cyclic voltammetric peaks for Hb Fe (III)/Fe (II) redox couple in a pH 7.0 phosphate buffer. The formal potential of Hb heme Fe (III)/Fe (II) couple varied linearly with the increase of pH in the range of 5.0-9.0 with a slope of 54 mV pH (-1), which implied that a proton transfer was accompanied with each electron transfer in the electrochemical reaction. Position of Soret absorption band of Hb-PAN film suggested that the Hb kept its secondary structure similar to its native state in the PAN matrix. The Hb in PAN matrix acted as a biologic catalyst to catalyze the reduction of hydrogen peroxide. The electrocatalytic response showed a linear dependence on the H (2) O (2) concentration ranging from 8.3 x 10 (-6) to 5 x 10 (-4) mol L (-1) with a detection limit of 8.3 x 10 (-6) mol L (-1) at 3 sigma. The apparent Michaelis-Menten constant K (M)(app) for H (2) O (2) sensor was estimated to be 0.9 mmol L (-1). |
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