Counter electrode based on an ion-exchanger Donnan exclusion membrane for bioelectroanalysis

Area of Science:

• Bioelectroanalysis
• Electrochemical Sensing
• Membrane Science

Background:

• Ion-exchanger based Donnan exclusion membranes (IEDEM) are investigated as separators for electrodes in bioelectrochemical applications.
• IEDEM exhibit ideal non-polarizable behavior across a broad current density range when in contact with electrolyte solutions.
• This characteristic makes them suitable for use with counter or reference electrodes in various cell configurations.

Purpose of the Study:

• To characterize commercial anion-exchanging membranes for bioelectrochemical applications.
• To determine the limitations and performance of IEDEM in different electrode configurations.
• To evaluate the potential of IEDEM as a cost-effective alternative to traditional electrode materials in complex biological matrices.

Main Methods:

• Utilized chronopotentiometry as the primary readout protocol.
• Characterized four different electrode configurations, both with and without IEDEM.
• Assessed membrane performance by applying various current amplitudes to determine upper current limits.
• Measured analytes in human whole blood using IEDEM as a counter electrode.

Main Results:

• IEDEM demonstrated ideal non-polarizable behavior, comparable to configurations without membranes (drift: 0.0007 s(1/2)/scan, RSD: 1.71%).
• The upper current limit for the membranes was found to be approximately 10 mA (42.8 mA cm(-2)), significantly exceeding typical chronopotentiometric experiment requirements.
• Successfully determined calcium, protamine, and chloride in human whole blood, with results comparable to reference methods.

Conclusions:

• IEDEM function as effective non-polarizable separators in bioelectrochemical systems.
• These membranes offer a viable, high-performance alternative to expensive electrode materials for measurements in biofluid samples.
• The study highlights the potential of IEDEM for developing advanced, cost-efficient bioelectrochemical sensors, particularly for matrices containing lipids and proteins.