Direct electron transfer of glucose oxidase on the carbon nanotube electrode  

作　　者：CAI Chenxin CHEN Jing LU Tianhong 

机构地区：[1]Department of Chemistry, Nanjing Normal University, Nanjing 210097, China Department of Chemistry, Nanjing Normal University, Nanjing 210097, China Department of Chemistry, Nanjing Normal University, Nanjing 210097, China

出　　处：《Science China Chemistry》2004年第2期113-119,共7页中国科学（化学英文版）

基　　金：This work was supported by the National Natural Science Foundation of China(Grant No.20373027);the Foundation for Scientists Returned from Abroad directed under the Ministry of Education of China;the Natural Science Foundation of Education Committee of Jiangsu Province(Grant No.03KJA150055);the Excellent Talent Project of Personnel Department of Nanjing City of Jiangsu Province.

摘　　要：The direct electron transfer of glucose oxidase (GOx) immobilized onto the surface of the carbon nanotube (CNT)-modified glassy carbon (CNT/GC) electrode is reported. The direct electron transfer rate of GOx is greatly enhanced when it was immobilized onto the surface of CNT/GC electrode. Cyclic voltammetric results show a pair of well-defined and nearly symmetric redox peaks, which corresponds to the direct electron transfer of GOx, with the formal potential (E 0′), which is almost independent on the scan rates, of about ?0.456 V (vs. SCE) in the phosphate buffer solution (pH 6.9). The apparent heterogeneous electron transfer rate constant (ks) of GOx at the CNT/GC electrode surface is estimated to be (1.74 ± 0.42) s-1, which is much higher than that reported previously. The dependence of E 0′ on solution pH indicates that the direct electron transfer of GOx is a two-electron-transfer coupled with two-proton-transfer reaction process. The experimental results also demonstrate that the immobilized GOx retains its bioelectrocatalytic activity toward the oxidation of glucose. The method presented here can be easily extended to obtain the direct electrochemistry of other enzymes or proteins.The direct electron transfer of glucose oxidase (GOx) immobilized onto the surface of the carbon nanotube (CNT)-modified glassy carbon (CNT/GC) electrode is reported. The di-rect electron transfer rate of GOx is greatly enhanced when it was immobilized onto the surface of CNT/GC electrode. Cyclic voltammetric results show a pair of well-defined and nearly sym-metric redox peaks, which corresponds to the direct electron transfer of GOx, with the formal potential 0()E, which is almost independent on the scan rates, of about 0.456 V (vs. SCE) in the phosphate buffer solution (pH 6.9). The apparent heterogeneous electron transfer rate con-stant (ks) of GOx at the CNT/GC electrode surface is estimated to be (1.74 ?0.42) s-1, which is much higher than that reported previously. The dependence of 0E on solution pH indicates that the direct electron transfer of GOx is a two-electron-transfer coupled with two-proton-transfer reaction process. The experimental results also demonstrate that the immobilized GOx retains its bioelectrocatalytic activity toward the oxidation of glucose. The method presented here can be easily extended to obtain the direct electrochemistry of other enzymes or proteins.

关 键 词：carbon nanotube  chemically modified electrode  direct electrochemistry  bioelectrocatalysis  GLUCOSE oxidase  glucose. 

分 类 号：O6[理学—化学]