Ultratrace PFAS Detection Using Amplifying Fluorescent Polymers.

Area of Science:

• Environmental Chemistry
• Polymer Science
• Analytical Chemistry

Background:

• Per- and poly(fluoroalkyl) substances (PFAS) are persistent environmental pollutants with adverse health effects, even at ultratrace concentrations (ng·L⁻¹).
• Current methods for PFAS detection are complex, require specialized equipment, and are unsuitable for on-site monitoring in distributed water systems.

Purpose of the Study:

• To develop and evaluate novel amplifying fluorescent polymers (AFPs) for selective, on-site detection of specific PFAS compounds.
• To demonstrate the capability of AFPs to detect perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) at environmentally relevant ultratrace concentrations.

Main Methods:

• Synthesis of highly fluorinated AFPs with poly(p-phenylene ethynylene) and polyfluorene backbones containing pyridine-based selectors.
• Investigation of the fluorescence response of AFPs to PFAS via a proton-transfer reaction mechanism, leading to spectral red-shifting.
• Evaluation of AFPs in thin-film and nanoparticle formats for selective PFAS detection in various water types (milliQ, DI, well water).

Main Results:

• AFPs selectively detect PFOA and PFOS at ng·L⁻¹ concentrations.
• Thin-film AFPs detect PFAS at approximately 1 ppb, while nanoparticle forms detect down to approximately 100 ppt.
• The performance of AFPs was consistent across different water matrices, unaffected by water type.

Conclusions:

• AFPs represent a promising sensing technology for the selective, on-site detection of aqueous PFAS at ultratrace levels.
• This approach simplifies PFAS monitoring in distributed water infrastructures, overcoming limitations of current methods.
• The developed AFPs offer a viable solution for real-time environmental monitoring of these critical pollutants.