Ultra-low LOD H₂O₂ Sensor Based on Synergistic Nernst Potential Effect

Area of Science:

• Biomedical Engineering
• Materials Science
• Analytical Chemistry

Background:

• Accurate detection of hydrogen peroxide (H₂O₂) is crucial for food processing and biomedical research.
• Organic electrochemical transistors (OECTs) offer significant signal amplification for biochemical sensing.
• Existing H₂O₂ detection methods require improvement in sensitivity and applicability.

Purpose of the Study:

• To develop a highly sensitive OECT-based sensor for detecting hydrogen peroxide (H₂O₂).
• To investigate the synergistic effects of material composition and catalytic mechanisms for enhanced detection.
• To demonstrate the practical application of the sensor in real-world samples and for related analytes.

Main Methods:

• Fabrication of an OECT using stacked PEDOT:BTB/PEDOT:PSS as the semiconducting channel.
• Utilizing a platinum gate electrode for catalyzing H₂O₂ and BTB interaction for Nernst potential generation.
• Development of a microsystem with signal processing and a mobile app for sensor integration and testing.

Main Results:

• Achieved an ultra-low limit of detection (LOD) for H₂O₂ down to 1.8 × 10⁻¹² M.
• Demonstrated the sensor's reliability by testing on commercial milk samples.
• Successfully detected glucose with a LOD of 8.82 × 10⁻¹¹ M, showcasing broader applicability.

Conclusions:

• The developed OECT sensor provides a highly sensitive and reliable method for H₂O₂ detection.
• The synergistic catalytic mechanism significantly enhances sensor performance.
• The methodology is adaptable for detecting various analytes involved in enzyme-catalyzed reactions.