Handheld Crop Pest Sensor Using Binary Catalyst-Loaded Nano-SnO₂ Particles for Oxidative Signal Amplification.

Area of Science:

• Agricultural Science
• Materials Science
• Sensor Technology

Background:

• Pest management in agriculture faces challenges due to the need for early detection of infestation.
• Crops release specific volatile organic compounds (VOCs) in response to pest attacks, which can be used as early warning signals.

Purpose of the Study:

• To develop a highly sensitive and selective chemoresistive sensor for early detection of pest volatiles.
• To amplify the sensor's signal for detecting low concentrations of pest-induced volatiles.
• To create a portable device for on-site pest detection.

Main Methods:

• Synthesis of binary catalyst-loaded SnO2 nanoparticles (<5 nm) for enhanced capture and oxidation of volatiles.
• Utilized extended X-ray absorption fine-structure spectroscopy (EXAFS) to characterize the Sn-Fe-Pt bond and its catalytic properties.
• Integrated a molecular sieve filter for selective detection of target volatiles and coupled with a mobile power bank for portability.

Main Results:

• Achieved detection of pest volatiles at concentrations as low as approximately 120 ppb.
• Demonstrated repeated capture and oxidation of volatiles, amplifying the chemoresistive signal.
• Ensured high selectivity for detecting *Tuta absoluta* infestation in tomato by filtering non-target volatiles.

Conclusions:

• The developed nanoparticle-based sensor offers high sensitivity and selectivity for early pest detection in agriculture.
• The portable device enables rapid, on-site monitoring, facilitating timely pest management strategies.
• This technology has the potential to significantly reduce crop losses due to pests.