Carbon nanotube mat as mediator-less glucose sensor electrode

Area of Science:

• Electrochemistry
• Biosensors
• Nanomaterials

Background:

• Carbon nanotube (CNT) mats offer excellent electrical conductivity and mechanical strength, making them suitable for electrode and catalyst support applications.
• Direct electron transfer in glucose oxidase (GOx) is crucial for efficient biosensing.
• Conventional CNT-dispersed electrodes involve complex preparation processes.

Purpose of the Study:

• To demonstrate direct electron transfer of glucose oxidase (GOx) on a carbon nanotube (CNT) mat electrode.
• To develop a simpler preparation method for CNT-based sensor electrodes.
• To evaluate the performance of the GOx-CNT mat biosensor for glucose detection.

Main Methods:

• Covalent immobilization of GOx onto an oxidized CNT mat.
• Characterization using Attenuated Total Reflectance Fourier Transform-Infrared (ATR-FTIR) spectroscopy.
• Electrochemical analysis including cyclic voltammetry and amperometry.

Main Results:

• ATR-FTIR confirmed the immobilization of GOx, showing amide band peaks.
• Cyclic voltammetry revealed well-defined redox peaks with a formal potential of -0.425 V (vs. Ag/AgCl).
• The biosensor exhibited a linear response to glucose from 0.2 mM to 2.18 mM with a sensitivity of 4.05 microA mM(-1) cm(-2) and a Michaelis-Menten constant of 2.18 mM.

Conclusions:

• The GOx-CNT mat electrode facilitates direct electron transfer and retains catalytic activity.
• The simplified preparation process offers advantages over conventional methods.
• The developed biosensor demonstrates promising performance for glucose monitoring.