Glucose electrodes based on cross-linked [Os(bpy)2Cl]+/2+ complexed poly(1-vinylimidazole) films

Area of Science:

• Electrochemistry
• Materials Science
• Biosensors

Background:

• Development of advanced enzyme electrodes is crucial for accurate biosensing.
• Redox hydrogels offer tunable properties for electrochemical applications.

Purpose of the Study:

• To describe novel enzyme electrodes based on redox hydrogels.
• To investigate the influence of polymer composition and environmental factors on electrode performance.
• To evaluate the glucose electrooxidation capabilities of the developed electrodes.

Main Methods:

• Complexation of poly(1-vinylimidazole) (PVI) with [Os(bpy)2Cl]+ and cross-linking with poly(ethylene glycol) diglycidyl ether.
• Incorporation of glucose oxidase (GOX) via covalent bonding during cross-linking.
• Electrochemical characterization of electron diffusion coefficients (De) and glucose electrooxidation currents.

Main Results:

• Electron diffusion coefficients (De) in redox hydrogels increased with osmium content and were affected by pH and ionic strength.
• Glucose electrodes exhibited efficient glucose electrooxidation at > 150 mV (SCE).
• Steady-state glucose electrooxidation current densities reached 400 microA/cm2 with 39% GOX, showing selectivity in the presence of interferents.

Conclusions:

• The developed redox hydrogel enzyme electrodes show promising performance for glucose sensing.
• Electrode properties can be tuned by adjusting osmium content, cross-linking, and environmental conditions.
• The electrodes demonstrate high sensitivity and selectivity, suitable for biosensing applications.