A Multiemission MOF-Based Fluorescent Sensor Array Functionalized with pH-Sensitive Dyes for Highly Sensitive...

Area of Science:

• Environmental Chemistry
• Materials Science
• Analytical Chemistry

Background:

• Per- and polyfluoroalkyl substances (PFASs) pose global environmental and health risks due to their persistence.
• Sensitive detection and discrimination of PFASs in aqueous systems are crucial for monitoring and mitigation.

Purpose of the Study:

• To develop a highly sensitive fluorescent sensor array for detecting and identifying multiple PFASs.
• To utilize zirconium-based metal-organic frameworks (Zr-MOFs) as hosts for pH-sensitive dyes to create stable fluorescent composites.

Main Methods:

• Synthesis of UiO-67-NH2 and PCN-999 Zr-MOFs via solvothermal method.
• In situ encapsulation of Nile Red, fluorescein isothiocyanate (FITC), and rhodamine 6G derivative (RGH) into MOF structures.
• Construction of a fluorescent sensor array using FR@UiO-67-NH2 and RGH@PCN-999 composites.

Main Results:

• The fluorescent composites FR@UiO-67-NH2 and RGH@PCN-999 exhibited excellent water stability and luminescence persistence.
• The sensor array achieved sensitive detection and identification of six PFASs with a limit of detection as low as 21.8 nM.
• Accurate discrimination of PFASs and their multicomponent mixtures in complex matrices like tap water and lake water was demonstrated.

Conclusions:

• The developed fluorescent sensor array offers a promising platform for sensitive and selective detection of PFASs.
• The array's ability to analyze PFASs in real-world water samples highlights its practical applicability.
• Further investigation into the fluorescence quenching mechanisms is warranted.