Highly sensitive and reusable Pt-black microfluidic electrodes for long-term electrochemical sensing

Area of Science:

• Electrochemistry
• Materials Science
• Microfluidics

Background:

• Developing stable and sensitive electrodes is crucial for electrochemical sensing.
• Microfluidic devices require robust electrode materials for reliable performance.
• Protecting electrode layers from degradation is a key challenge in sensor design.

Purpose of the Study:

• To fabricate and evaluate highly sensitive, stable, and reusable microfluidic electrodes.
• To assess the performance of platinum-black electrodes for detecting hydrogen peroxide and hydroquinone.
• To demonstrate the effectiveness of microfluidic flow for electrode reactivation.

Main Methods:

• Fabrication of microfluidic electrodes with a platinum-black layer on gold.
• Electrochemical characterization using cyclic voltammetry (CV) in flowing buffer.
• Evaluation of electrode sensitivity, dynamic range, and detection limits for H2O2 and hydroquinone.
• Assessment of long-term stability and reusability over 30 days.

Main Results:

• Achieved high sensitivity and a wide linear dynamic range for H2O2 and hydroquinone detection.
• Established low detection limits of 10 nM for H2O2 and 100 nM for hydroquinone.
• Demonstrated long-term stability (30+ days) and reusability of the electrodes.
• Confirmed effective protection against electrooxidation of the chromium adhesion layer.

Conclusions:

• The developed microfluidic electrodes exhibit excellent sensitivity, stability, and reusability.
• The platinum-black electrode architecture is suitable for long-term electrochemical detection in microfluidic systems.
• Microfluidic flow enables efficient desorption and reactivation, enhancing electrode longevity for biosensing and immunoassays.