Detection of Per- and Polyfluoroalkyl Substances (PFAS) by Interrupted Energy Transfer

Area of Science:

• Environmental Science
• Analytical Chemistry
• Materials Science

Background:

• Per- and polyfluoroalkyl substances (PFAS) are widespread environmental contaminants of significant concern.
• Current continuous monitoring technologies for PFAS in water distribution systems are lacking.

Purpose of the Study:

• To develop a selective ratiometric sensing approach for detecting perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) in aqueous environments.
• To create a sensor capable of continuous monitoring within water distribution infrastructures.

Main Methods:

• Utilized a highly fluorinated poly(p-phenylene ethynylene) and an embedded fluorinated squaraine dye for ratiometric sensing.
• Leveraged excitonic transport and Dexter energy transfer mechanism, modulated by PFAS interaction with polymer-dye electronic coupling.
• Evaluated sensor performance in spin-coated films and polymer nanoparticles.

Main Results:

• Achieved selective detection of PFOA and PFOS at μg/L concentrations.
• Demonstrated selective detection limits of approximately 150 ppb for polymer films and 50 ppb for polymer nanoparticles.
• Confirmed sensor functionality is independent of water type, showing similar responses in milliQ and well water.

Conclusions:

• The developed ratiometric sensing approach provides a promising method for continuous PFAS monitoring.
• The polymer/dye system exhibits selective and sensitive detection of key PFAS compounds.
• The sensor's robustness across different water types supports its potential application in real-world water monitoring scenarios.