Covalently immobilized enzymes on biocompatible polymers for amperometric sensor applications

Area of Science:

• Biomaterials Science
• Electrochemistry
• Biosensor Technology

Background:

• Enzyme immobilization is crucial for biosensor development.
• Copolymer membranes offer tunable properties for biosensor applications.
• Amperometric sensors rely on electrochemical detection of enzyme reaction products.

Purpose of the Study:

• To develop novel amperometric biosensors for glucose and choline detection.
• To immobilize glucose oxidase or choline oxidase onto 2-hydroxyethyl and glycidyl methacrylate copolymer membranes.
• To evaluate the analytical performance and stability of the developed enzyme-modified membranes.

Main Methods:

• Covalent immobilization of enzymes onto copolymer membranes via gamma irradiation.
• Fabrication of amperometric sensors using modified membranes on Clark-type or platinum electrodes.
• Electrochemical measurements for quantifying oxygen or hydrogen peroxide.
• Analysis of glucose and choline in standard solutions using developed sensors.

Main Results:

• Linear calibration curves were obtained for glucose and choline detection.
• Sensors exhibited response times under 2 minutes.
• Diffusion-limiting effects of membranes increased linear ranges compared to conventional biosensors.
• Optimum copolymer composition enhanced electrochemical response and enzyme activity retention.

Conclusions:

• The developed enzyme-immobilized copolymer membranes provide a stable and efficient platform for amperometric biosensors.
• The enhanced linear ranges and rapid response times signify improved analytical performance.
• The biosensors demonstrate long-term stability, with minimal response decrease after 3 months of use.