Quenching-based electrochemiluminescence detection of chlorpyrifos using a portable sensor platform

Area of Science:

• Analytical Chemistry
• Biosensors
• Materials Science

Background:

• Chlorpyrifos (CPF) is a widely used organophosphate pesticide with significant neurotoxic effects.
• Its presence in food poses public health risks, demanding sensitive detection methods.
• Existing detection methods often lack the required speed, sensitivity, or reliability for routine food safety monitoring.

Purpose of the Study:

• To design and validate an electrochemiluminescence (ECL) sensor for ultrasensitive chlorpyrifos detection.
• To develop a rapid, sensitive, and reliable method for detecting CPF in food matrices.
• To address public health concerns regarding pesticide residues in food products.

Main Methods:

• Fabrication of an ECL sensing interface using carboxyl-functionalized multiwalled carbon nanotubes (MWCNTs) and [Ru(bpy)₃]²⁺ complexes on a screen-printed carbon electrode.
• Utilizing a quenching-based mechanism involving 2-(dibutylamino)ethanol (DBAE) and [Ru(bpy)₃]²⁺, where CPF suppresses ECL emission.
• Optimization of analytical parameters and validation using honey samples to assess real-world applicability.

Main Results:

• Achieved an ultra-low limit of detection (LoD) of 0.24 ± 0.05 pM for CPF.
• Demonstrated a wide linear dynamic range from 0.73 ± 0.13 pM to 100 ± 1.49 pM.
• Exhibited high accuracy in honey samples (96.26–101.45% recovery) and excellent sensor stability over 30 days.

Conclusions:

• The developed ECL sensor is an efficient tool for detecting chlorpyrifos residues in food.
• The combination of MWCNT signal amplification and the quenching mechanism provides ultrasensitive detection.
• The sensor shows promise for real-time food safety monitoring and regulatory compliance.