Fluorescent molecularly imprinted polymer particles for glyphosate detection using phase transfer agents

Area of Science:

• Analytical Chemistry
• Materials Science
• Environmental Science

Background:

• Highly polar pesticides like Glyphosate (GPS) pose challenges for direct detection in organic solvents.
• Developing sensitive and selective detection methods for GPS is crucial for environmental monitoring and public health.

Purpose of the Study:

• To develop a direct fluorescence detection method for Glyphosate (GPS) using molecularly imprinted polymers (MIPs).
• To improve the solubility of GPS in organic solvents for imprinting.
• To achieve sensitive and selective quantification of GPS in aqueous samples.

Main Methods:

• Molecular imprinting of Glyphosate (GPS) using fluorescent probes and lipophilic counterions (tetrabutylammonium (TBA+) and tetrahexylammonium (THA+)).
• Preparation of fluorescent molecularly imprinted polymer (MIP) shells on silica particles.
• Fluorescence titration for evaluating MIP binding and selectivity.
• Biphasic assay for direct detection and quantification in water.

Main Results:

• Successfully imprinted GPS-TBA and GPS-THA complexes into fluorescent MIP shells.
• GPS-THA MIPs demonstrated superior selectivity against competing molecules compared to GPS-TBA MIPs.
• The biphasic assay enabled direct fluorescence detection and quantification of GPS in water with a limit of detection of 1.45 µM.
• Achieved a linear range of 5-55 µM, consistent with WHO guidelines for daily intake.

Conclusions:

• The developed MIP-based fluorescence method provides a sensitive and selective approach for detecting Glyphosate (GPS).
• The use of THA+ as a counterion enhances phase transfer efficiency and detection capabilities in aqueous samples.
• This method holds promise for environmental monitoring of Glyphosate (GPS) in water sources.