Emerging Dual-Gate FET Sensor Paradigm for Ultra-Low Concentration Cortisol Detection in Complex Bioenvironments

Area of Science:

• Biomedical Engineering
• Sensor Technology
• Analytical Chemistry

Background:

• Cortisol monitoring is crucial for stress response and health condition assessment.
• Conventional cortisol detection methods lack sensitivity and reliability at low concentrations.
• Non-invasive monitoring of cortisol is desirable for diagnostic applications.

Purpose of the Study:

• To develop a novel, highly sensitive cortisol detection method.
• To enhance cortisol detection sensitivity using dual-gate field-effect transistor (DG-FET) sensors.
• To validate the reliability and stability of the DG-FET sensor in complex environments.

Main Methods:

• Fabrication of a DG-FET sensor with a SnO2 thin film-based extended-gate.
• Immobilization of monoclonal antibodies for cortisol recognition.
• Evaluation of sensor performance in single-gate and dual-gate modes.
• Testing sensor stability and reliability in artificial saliva with interfering substances.

Main Results:

• The DG-FET sensor demonstrated significantly enhanced sensitivity (243.8 mV/dec) compared to single-gate mode (14.3 mV/dec).
• Achieved a low limit of detection for cortisol at 276 pM.
• Validated sensor reliability and stability in artificial saliva, showing accurate detection amidst interfering substances.

Conclusions:

• The developed DG-FET sensor offers a paradigm shift for high-sensitivity cortisol detection.
• This technology enables precise monitoring of cortisol at ultra-low concentrations.
• The DG-FET sensor shows great potential for bioassays requiring high sensitivity and reliability in complex biological samples.