Electropolymerization of preoxidized catecholamines on Prussian blue matrix to immobilize glucose oxidase for sensitive amperometric biosensing.
We examine here the electropolymerization of electrochemically or chemically preoxidized catecholamines in glucose oxidase (GOx)-containing neutral solutions to efficiently immobilize the enzyme at Prussian blue-modified Au electrodes for sensitive amperometric biosensing of glucose. The electrochemical quartz crystal microbalance (EQCM) was used to track various electrode-modification processes. The optimized poly(dopamine)-based glucose biosensor displayed a sensitivity of 35 microA mM(-1) cm(-2) and a limit of detection of 0.3 microM at 0.7 V vs. SCE, and similar results were obtained at -0.05 V vs. SCE, which are obviously better than those from preoxidation-free conventional electropolymerization. The immobilized GOx retained high enzymatic specific activity, as quantified by UV-vis spectrophotometry and EQCM. L-noradrenaline could similarly electropolymerize and the resultant enzyme film gave equivalent biosensing characteristics, but the electropolymerization of EP was less efficient and the resultant enzyme film showed notably poorer performance.
Chen
Chao
C
Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, PR China.
Fu
Yingchun
Y
Xiang
Canhui
C
Xie
Qingji
Q
Zhang
Qingfang
Q
Su
Yuhua
Y
Wang
Lihua
L
Yao
Shouzhuo
S
D015374:Biosensing Techniques / Q000295:instrumentation*; D002395:Catecholamines / Q000737:chemistry*; D004563:Electrochemistry / Q000295:instrumentation*; D004800:Enzymes, Immobilized / Q000737:chemistry; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005295:Ferrocyanides / Q000737:chemistry*; D005947:Glucose / Q000032:analysis* / Q000737:chemistry; D005949:Glucose Oxidase / Q000737:chemistry*; D010084:Oxidation-Reduction; D011108:Polymers / Q000737:chemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D002395:Catecholamines; D004800:Enzymes, Immobilized; D005295:Ferrocyanides; D011108:Polymers; D005949:Glucose Oxidase; D005947:Glucose; C000170:ferric ferrocyanide