Interfacial electron transfer of glucose oxidase on poly(glutamic acid)-modified glassy carbon electrode and glucose sensing.
The interfacial electron transfer of glucose oxidase (GOx) on a poly(glutamic acid)-modified glassy carbon electrode (PGA/GCE) was investigated. The redox peaks measured for GOx and flavin adenine dinucleotide (FAD) are similar, and the anodic peak of GOx does not increase in the presence of glucose in a mediator-free solution. These indicate that the electroactivity of GOx is not the direct electron transfer (DET) between GOx and PGA/GCE and that the observed electroactivity of GOx is ascribed to free FAD that is released from GOx. However, efficient electron transfer occurred if an appropriate mediator was placed in solution, suggesting that GOx is active. The PGA/GCE-based biosensor showed wide linear response in the range of 0.5-5.5 mM with a low detection limit of 0.12 mM and high sensitivity and selectivity for measuring glucose.
School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China. Electronic address: zhou1300222@outlook.com.
Xuechou
X
Zhou
School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
Bingcan
B
Tan
School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
Xinyu
X
Zheng
School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
Dexian
D
Kong
School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Engineering Laboratory of Animal Pharmaceuticals of Fujian Province, Fuzhou 350002, China. Electronic address: lql3388@126.com.
Qinglu
Q
Li
D001234:Aspergillus niger / Q000201:enzymology; D015374:Biosensing Techniques; D001786:Blood Glucose / Q000032:analysis; D002138:Calibration; D002681:China; D055664:Electrochemical Techniques; D004566:Electrodes; D004579:Electron Transport; D004800:Enzymes, Immobilized / Q000378:metabolism*; D005182:Flavin-Adenine Dinucleotide / Q000378:metabolism*; D005656:Fungal Proteins / Q000378:metabolism*; D005947:Glucose / Q000032:analysis / Q000378:metabolism*; D005949:Glucose Oxidase / Q000378:metabolism*; D006873:Hydroquinones / Q000737:chemistry; D007202:Indicators and Reagents / Q000737:chemistry; D007700:Kinetics; D057230:Limit of Detection; D010084:Oxidation-Reduction; D011099:Polyglutamic Acid / Q000737:chemistry; D013499:Surface Properties
D001786:Blood Glucose; D004800:Enzymes, Immobilized; D005656:Fungal Proteins; D006873:Hydroquinones; D007202:Indicators and Reagents; D005182:Flavin-Adenine Dinucleotide; D011099:Polyglutamic Acid; D005949:Glucose Oxidase; D005947:Glucose; C004601:quinhydrone
Glucose oxidase; Glucose sensing; Interfacial electron transfer; Poly(glutamic acid)-modified electrode