Glucose oxidase sandwiched between pHEMA layers: a continuous flow reactor application

Area of Science:

• Biochemistry
• Biomaterials Science
• Chemical Engineering

Background:

• Glucose oxidase is a crucial enzyme for glucose detection and biofuel cells.
• Enzyme immobilization is key to enhancing stability and reusability.
• Poly(2-hydroxyethyl methacrylate) (PHEMA) offers a promising matrix for enzyme entrapment.

Purpose of the Study:

• To optimize conditions for high enzyme activity and entrapment of glucose oxidase within PHEMA membranes.
• To characterize the kinetic properties and stability of immobilized glucose oxidase.
• To design and evaluate a continuous flow membrane reactor for immobilized glucose oxidase.

Main Methods:

• Entrapment of glucose oxidase within PHEMA membranes of varying thickness.
• Optimization of immobilization conditions for maximum enzyme activity and entrapment efficiency.
• Design and implementation of a continuous flow membrane reactor.
• Kinetic analysis (Vmax, Km) and stability testing of native and immobilized enzymes.

Main Results:

• Optimal entrapment achieved with a 78-micron thick PHEMA membrane.
• Immobilized glucose oxidase exhibited altered kinetic parameters (Vmax, Km) compared to the native enzyme.
• Enzyme poisoning was observed at high substrate concentrations.
• Immobilized enzyme showed a shift in optimal pH and temperature profiles.
• The immobilized enzyme retained 80% of its activity for at least 3 months in dry form.

Conclusions:

• PHEMA membrane entrapment is an effective method for glucose oxidase immobilization, enhancing stability.
• The developed continuous flow membrane reactor demonstrates potential for practical applications.
• Further studies are needed to mitigate enzyme poisoning at high substrate concentrations.