Premium
Direct Electron Transfer of Glucose Oxidase and Glucose Biosensor Based on Nano‐structural Attapulgite Clay Matrix
Author(s) -
Xu Jiming,
Han Wenxia,
Yin Qifan,
Song Jie,
Zhong Hui
Publication year - 2009
Publication title -
chinese journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.28
H-Index - 41
eISSN - 1614-7065
pISSN - 1001-604X
DOI - 10.1002/cjoc.200990368
Subject(s) - chemistry , glucose oxidase , biosensor , redox , electrochemistry , electron transfer , ferrocene , immobilized enzyme , dehydrogenase , nuclear chemistry , inorganic chemistry , glassy carbon , cyclic voltammetry , electrode , enzyme , organic chemistry , biochemistry
The direct electrochemistry of glucose oxidase (GOD) was achieved based on the immobilization of GOD on a natural nano‐structural attapulgite (ATP) clay film modified glassy carbon (GC) electrode. The immobilized GOD displayed a pair of well‐defined quasi‐reversible redox peaks with a formal potential ( E 0′ ) of −457.5 mV (vs. SCE) in 0.1 mol·L −1 pH 7.0 phosphate buffer solution. The peak current was linearly dependent on the scan rate, indicating that the direct electrochemistry of GOD in that case was a surface‐controlled process. The immobilized glucose oxidase could retain bioactivity and catalyze the oxidation of glucose in the presence of ferrocene monocarboxylic acid (FMCA) as a mediator with the apparent Michaelis‐Menten constant K app m of 1.16 mmol·L −1 . The electrocatalytic response showed a linear dependence on the glucose concentration ranging widely from 5.0×10 −6 to 6.0×10 −4 mol·L −1 (with correlation coefficient of 0.9960). This work demonstrated that the nano‐structural attapulgite clay was a good candidate material for the direct electrochemistry of the redox‐active enzyme and the construction of the related enzyme biosensors. The proposed biosensors were applied to determine the glucose in blood and urine samples with satisfactory results.