Extended gate field-effect-transistor for sensing cortisol stress hormone

Area of Science:

• Biomedical Engineering
• Materials Science
• Analytical Chemistry

Background:

• Cortisol is a key stress hormone and glucocorticoid produced by adrenal glands.
• Real-time monitoring of cortisol is crucial for understanding stress responses and circadian rhythms.
• Existing methods for cortisol detection often lack the sensitivity, selectivity, or real-time capabilities required for wearable applications.

Purpose of the Study:

• To develop a wearable, label-free electrochemical sensor for cortisol detection.
• To utilize a platinum/graphene aptamer extended gate field-effect transistor (EG-FET) for enhanced cortisol recognition.
• To demonstrate the sensor's capability for real-time monitoring of cortisol in human sweat.

Main Methods:

• Fabrication of a platinum/graphene aptamer EG-FET sensor.
• Label-free detection of cortisol in biological buffers.
• Characterization of sensor performance, including sensitivity, detection limit, dynamic range, selectivity, and stability.
• Testing the sensor's performance with human sweat samples.

Main Results:

• The EG-FET sensor demonstrated hysteresis-free operation with high voltage and current sensitivity.
• Achieved a low detection limit of 0.2 nM for cortisol over a wide concentration range (1 nM to 10 µM).
• Exhibited negligible drift and high selectivity, with a dynamic range suitable for human sweat analysis.

Conclusions:

• The developed wearable EG-FET sensor offers a promising platform for non-invasive, real-time cortisol monitoring.
• The sensor's high sensitivity, selectivity, and wide dynamic range make it suitable for tracking circadian cortisol rhythms in sweat.
• This technology could advance personalized stress management and health monitoring.