Amperometric enzyme electrodes.

Area of Science:

• Electrochemistry
• Biotechnology
• Biosensors

Background:

• Amperometric enzyme electrodes are crucial for biochemical analysis.
• Developing efficient and selective biosensors is an ongoing challenge.
• Existing methods may require membranes or lack in vivo applicability.

Purpose of the Study:

• To describe three distinct types of amperometric enzyme electrodes.
• To demonstrate their application in detecting various analytes, including biomolecules and toxic gases.
• To investigate the underlying mechanisms of enzyme oxidation and sensor performance.

Main Methods:

• Utilizing conducting organic-salt electrodes for enzyme immobilization and redox reactions.
• Developing sensors for NADH oxidation, ethanol, bile acids, and flavoenzymes.
• Investigating heterogeneous redox catalysis for enzyme oxidation.
• Designing sensors for in vivo glucose monitoring in rats.
• Employing enzyme inhibition of cytochrome oxidase for toxic gas detection (H2S, HCN).

Main Results:

• Successful development of sensors for ethanol and bile acids.
• Demonstration of direct oxidation of five different flavoenzymes on the electrode surface.
• Confirmation of heterogeneous redox catalysis and strong enzyme adsorption, enabling membrane-less microelectrodes.
• Real-time in vivo monitoring of glucose levels in rat brains.
• Detection of low concentrations of H2S and HCN via enzyme inhibition.

Conclusions:

• Conducting organic-salt electrodes offer a versatile platform for amperometric enzyme biosensors.
• The developed sensors show promise for both in vitro biochemical analysis and in vivo monitoring.
• Enzyme inhibition provides a sensitive method for detecting toxic gases.