Enhanced electrochemical oxygen reduction-based glucose sensing using glucose oxidase on nanodendritic poly[meso-tetrakis(2-thienyl)porphyrinato]cobalt(II)-SWNTs composite electrodes.
The direct electrochemistry of glucose oxidase immobilized on a nanodendritic poly[meso-tetrakis(2-thienyl)porphyrinato]cobalt(II)-single walled carbon nanotube modified glassy carbon electrode (pCoTTP-SWNTs-Nafion-GOD/GCE) is reported. The immobilized GOD retained its activity and exhibited a surface controlled, reversible two-proton and two-electron transfer reaction with a fast heterogeneous electron transfer rate constant (ks) of 1.01 s(-1). The pCoTTP-SWNTs-Nafion matrix also showed an extremely low peak potential of -0.2 V vs. Ag/AgCl and strong response with respect to oxygen reduction. This forms the basis for the use of the pCoTTP-SWNTs-Nafion-GOD composite as a sensing platform for oxygen reduction-based glucose detection. The apparent Michaelis-Menten constant (Km,app) was estimated to be as low as 0.98 mM. A linear range up to 1mM glucose with a low detection limit of 5.33 μM (S/N=3) and a high sensitivity of 16.57 μA mM(-1) cm(-2) was achieved. The biosensor also shows excellent selectivity against 0.2 mM uric acid and ascorbic acid. These results indicate that the pCoTTP-SWNTs-Nafion-GOD/GCE has potential application in sensitive and selective glucose detection.
Chen
Wei
W
Department of Chemical, Materials and Biomolecular Engineering, University of Connecticut, Storrs, CT 06269-3222, USA.
Ding
Yu
Y
Akhigbe
Joshua
J
Brückner
Christian
C
Li
Chang Ming
CM
Lei
Yu
Y
D015374:Biosensing Techniques / Q000295:instrumentation*; D003217:Conductometry / Q000295:instrumentation*; D050091:Dendrimers / Q000737:chemistry*; D004800:Enzymes, Immobilized / Q000737:chemistry; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005947:Glucose / Q000032:analysis*; D005949:Glucose Oxidase / Q000737:chemistry*; D008839:Microelectrodes; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000295:instrumentation; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010084:Oxidation-Reduction
D050091:Dendrimers; D004800:Enzymes, Immobilized; D037742:Nanotubes, Carbon; D005949:Glucose Oxidase; D005947:Glucose