Metal-Organic Frameworks (MOFs)-Based Piezoelectric-Colorimetric Hybrid Sensor for Monitoring Green Leaf Volatiles

Area of Science:

• Analytical Chemistry
• Materials Science
• Agricultural Science

Background:

• Green leaf volatiles (GLVs) signal plant distress from insect attacks, but current detection methods are costly and lack real-time capabilities.
• An unmet need exists for affordable, portable, and highly sensitive sensors for real-time GLV monitoring.
• Early detection of GLVs is crucial for timely crop protection strategies.

Purpose of the Study:

• To develop a novel, multifunctional sensor for sensitive and selective detection of 1-hexanol, a key GLV.
• To integrate piezoelectric and colorimetric sensing mechanisms for enhanced detection performance.
• To create an affordable and portable device for real-time monitoring of plant stress indicators.

Main Methods:

• A piezoelectric micro quartz tuning fork (MQTF) was utilized as the core transducer.
• The MQTF prongs were functionalized with a hybrid sensing material combining metal-organic frameworks (MOFs) and thymol blue.
• Detection was achieved by monitoring both the colorimetric changes and the resonant frequency shifts of the MQTF upon 1-hexanol binding.

Main Results:

• The developed sensor demonstrated high sensitivity and selectivity for 1-hexanol detection across a wide concentration range (62.5 ppb to 250 ppm).
• Integration of piezoelectric and colorimetric signals significantly improved detection accuracy.
• The MOF-thymol blue hybrid material facilitated efficient 1-hexanol capture and signal transduction.

Conclusions:

• The novel colorimetric-piezoelectric sensor offers a sensitive, selective, and portable solution for real-time GLV detection.
• This technology has the potential to revolutionize early insect herbivore attack detection and crop protection.
• The sensor's cost-effectiveness and ease of fabrication make it suitable for practical agricultural applications.