Direct electron transfer of glucose oxidase immobilized on a mesoporous silica KIT-6 matrix to screen-printed electrodes.
The direct electron transfer of glucose oxidase (GOx) immobilized on a large-pore mesoporous silica KIT-6 matrix fixed to a screen-printed electrode (SPE) and its application as a disposable biosensor were studied. KIT-6 plays a vital role in this method through immobilizing GOx and facilitating the electron communication between the active centers of GOx and the surface of the SPE. GOx immobilized on KIT-6 maintains its bioactivity and structure and displays stable and well-defined redox peaks with a formal potential of -428 mV (vs. Saturated Calomel Electrode), with a heterogeneous electron transfer rate constant of 4.15 s(-1) in phosphate buffer (0.05 M, pH 6.0). Upon the addition of glucose into air-saturated phosphate buffer solution, the reduction peak current decreases, which can be used analytically for glucose detection. The biosensor exhibits a linear response to glucose concentration ranging from 0 to 2.83 mM and a sensitivity of 7.29 microA (mM)(-1) cm(-2) at an applied potential of -0.5 V. The present work provides a promising strategy for fabricating a novel and disposable mediator-free glucose biosensor, which could be potentially mass-produced through further development.
Zuo
Shaohua
S
Research Center of Analysis and Test and Institute of Advanced Materials, East China University of Science and Technology, Shanghai 200237, PR China.
Wu
Xianbo
X
Teng
Yuanjie
Y
Yuan
Huihui
H
Lan
Minbo
M
Lawrance
Geoffrey A
GA
Wei
Gang
G
D000327:Adsorption; D004566:Electrodes; D004583:Electrons; D004800:Enzymes, Immobilized / Q000737:chemistry*; D005949:Glucose Oxidase / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D012822:Silicon Dioxide / Q000737:chemistry*; D014961:X-Ray Diffraction
D004800:Enzymes, Immobilized; D012822:Silicon Dioxide; D005949:Glucose Oxidase