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Acid stability of carbon paste enzyme electrodes
Joseph Wang1, Mustafa Musameh, Jian-Wei Mo
1The Biodesign Institute, Department of Chemical and Materials Engineering, Arizona State University, Tempe, Arizona 85287-5801, USA. joseph.wang@asu.edu
Analytical Chemistry
|September 30, 2006
Summary
Carbon paste electrodes offer unique protection for enzymes against acidic conditions. This stability in amperometric biosensors is attributed to the hydrophobic paste environment and reduced enzyme mobility.
Area of Science:
- Electrochemistry
- Biochemistry
- Biosensor Technology
Background:
- Conventional biosensors often suffer from deactivation under harsh pH conditions.
- Enzyme stability is crucial for reliable biosensor performance.
Purpose of the Study:
- To investigate the protective effect of carbon paste electrodes on enzyme stability in acidic environments.
- To compare the acid resistance of carbon paste-based biosensors with conventional polymer-based biosensors.
Main Methods:
- Fabrication of carbon paste amperometric biosensors using glucose oxidase and polyphenol oxidase.
- Exposure of carbon paste enzyme electrodes and conventional polymer-based biosensors to strongly acidic conditions (pH ~2.0-2.5).
- Monitoring enzyme activity and response retention after acid stress.
Main Results:
- Carbon paste enzyme electrodes demonstrated remarkable resistance to acid deactivation.
- Enzymes in carbon paste electrodes retained full activity after prolonged exposure to pH 2.0-2.5.
- Conventional polymer-based biosensors rapidly lost significant response under similar acidic conditions.
Conclusions:
- Carbon paste electrodes provide unusual protection to enzymes against harsh pH.
- The hydrophobic paste environment, barrier properties of the pasting liquid, and reduced enzyme mobility contribute to enhanced acid stability.
- Carbon paste technology offers a promising approach for developing robust and stable amperometric biosensors.
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