Amino-Induced Microenvironment Modulation in Eu-MOFs Enabling Ratiometric Fluorescence Sensing of Sarin and Mustard...

Area of Science:

• Materials Science
• Chemistry
• Analytical Chemistry

Background:

• Chemical warfare agents (CWAs) pose significant global security threats.
• Real-time, sensitive detection technologies for CWAs are crucial.
• Metal-organic frameworks (MOFs) offer tunable properties for sensing applications.

Purpose of the Study:

• To develop amino-functionalized europium-based MOFs (Eu-MOFs) for simultaneous, ratiometric fluorescence detection of sarin and mustard gas simulants.
• To investigate the effect of amino functionalization on the sensing performance of Eu-MOFs.
• To elucidate the sensing mechanism at the molecular level.

Main Methods:

• Synthesis of Eu-MOFs with varying amino functionalization (SNNU-369, SNNU-370, SNNU-371).
• Ratiometric fluorescence spectroscopy for detecting diethyl chlorophosphite (DCP) and 2-chloroethyl ethyl sulfide (CEES).
• Mechanism studies involving photophysical characterization and computational analysis.

Main Results:

• Amino-functionalized SNNU-370 and SNNU-371 exhibited selective ratiometric fluorescence detection for DCP and CEES.
• Achieved low limits of detection (LOD): SNNU-370 (1 ppb for DCP, 1.5 ppm for CEES); SNNU-371 (0.3 ppm for DCP, 0.4 ppm for CEES).
• Demonstrated fast response times (≤120 s), good stability, and anti-interference capabilities.
• Identified suppressed charge transfer mechanisms leading to enhanced ligand-centered emission and distinct color changes.

Conclusions:

• Amino functionalization is key to developing high-performance Eu-MOF-based sensors for CWAs.
• The developed bifunctional MOF platform provides a promising approach for CWA detection.
• Insights gained facilitate the rational design of advanced molecular sensing materials.