Eye-Readable and Wearable Colorimetric Sensor Arrays for In Situ Monitoring of Volatile Organic Compounds

Area of Science:

• Materials Science
• Analytical Chemistry
• Biotechnology

Background:

• Colorimetric wearable sensors offer advantages like ease of use and cost-effectiveness for physiological monitoring.
• Existing sensors face limitations in detecting low concentrations of volatile organic compounds (VOCs) and are susceptible to interference.
• In situ detection of complex VOCs remains a challenge for current wearable technologies.

Purpose of the Study:

• To develop advanced wearable colorimetric sensing arrays for the in situ detection of complex VOCs.
• To overcome limitations in sensitivity and interference in current VOC detection methods.
• To demonstrate a practical application in monitoring fruit ripening through VOC analysis.

Main Methods:

• Fabrication of wearable colorimetric sensor arrays using dye/metal-organic framework (MOF) composites on nanofiber membranes.
• Integration of sensor elements within a microfluidic channel (polydimethylsiloxane - PDMS) for enhanced gas collection.
• Utilizing DenseNet classification for analyzing VOC data collected from fruit surfaces.

Main Results:

• Developed sensor arrays capable of specific recognition of multiple characteristic VOCs, including ethylene.
• Demonstrated successful in situ monitoring of VOC emissions from fruit surfaces.
• Validated the wearable sensing system's feasibility for tracking fruit ripening stages.

Conclusions:

• The developed wearable colorimetric sensor arrays show significant promise for in situ detection of complex VOCs.
• This technology offers a cost-effective and user-friendly approach for real-time monitoring applications.
• The system provides a proof of concept for non-invasive monitoring of biological processes like fruit ripening.