Immobilization of hemoglobin on SBA-15 applied to the electrocatalytic reduction of H2O2.
The direct electron transfer between hemoglobin (Hb) and an electrode was realized by first immobilizing the protein onto SBA-15. The results of the immobilization showed that the adsorption was pH-dependent with a maximum adsorption near the isoelectric point of the protein, and SBA-15 with a larger pore diameter showed greater adsorption capacity for Hb. UV-vis spectroscopy and nitrogen adsorption analysis indicated that Hb was adsorbed within the channel of SBA-15 and no significant denaturation occurred to the protein. The Hb/SBA-15 composite obtained was used for the fabrication of a Hb biosensor to detect hydrogen peroxide. A pair of well-defined redox peaks at -0.337 and -0.370 V on the Hb/SBA-15 composite modified glassy carbon electrode was observed, and the electrode reactions showed a surface-controlled process with a single proton transfer at a scan rate range from 20 to 1,000 mV/s. The sensor showed a fast amperometric response, a low detection limit (2.3 x 10(-9) M) and good stability for the detection of H(2)O(2). The electrochemical results indicated that the immobilized Hb still retained its biological activity.
Liu
Yuge
Y
Key Laboratory of Analytical Chemistry for Life Science, Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, People's Republic of China.
Xu
Qin
Q
Feng
Xiaomiao
X
Zhu
Jun-Jie
JJ
Hou
Wenhua
W
D000818:Animals; D002384:Catalysis; D002417:Cattle; D004566:Electrodes; D004583:Electrons; D006454:Hemoglobins / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D010084:Oxidation-Reduction; D012822:Silicon Dioxide / Q000737:chemistry*; D013057:Spectrum Analysis
D006454:Hemoglobins; C509969:SBA-15; D012822:Silicon Dioxide; D006861:Hydrogen Peroxide