Peroxidase-mimetic carbon dot based nanozyme hydrogel colorimetric sensor for visual trichlorfon detection

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Biotechnology

Background:

• Organophosphorus pesticides, like trichlorfon, pose significant environmental and public health risks.
• Accurate and sensitive detection methods are crucial for monitoring pesticide residues in food.
• Existing methods may lack the simplicity and portability required for on-site food safety assessments.

Purpose of the Study:

• To develop a visual sensing platform for the sensitive and rapid detection of trichlorfon.
• To create a portable colorimetric hydrogel kit for on-site trichlorfon residue analysis.
• To provide an accessible tool for food safety monitoring in agricultural products.

Main Methods:

• Utilized a carbon-based nanozyme (Fe-CDs) with peroxidase-mimetic activity and acetylcholinesterase (AChE).
• Exploited the inhibition of Fe-CDs by sulfhydryl compounds and AChE's decomposition of thiocholine (ATCh).
• Developed a colorimetric hydrogel kit with Fe-CDs, ATCh, and TMB, analyzed using smartphone technology.

Main Results:

• Achieved sensitive detection of trichlorfon with a linear range of 200–50,000 pM and a detection limit of 157.57 pM.
• Successfully applied the platform for trichlorfon detection in Chinese cabbage samples.
• Demonstrated the efficacy of the portable hydrogel kit for simple and rapid on-site detection.

Conclusions:

• The developed visual sensing platform offers a direct, simple, and rapid strategy for trichlorfon detection.
• The colorimetric hydrogel kit represents a potential on-site detection tool for food safety monitoring.
• This approach contributes to enhanced monitoring of pesticide residues in agricultural products.