Dual-Functional Eu-Metal-Organic Framework with Ratiometric Fluorescent Broad-Spectrum Sensing of Benzophenone-like...

Area of Science:

• Materials Science
• Coordination Chemistry
• Analytical Chemistry

Background:

• Developing dual-functional lanthanide-metal-organic frameworks (Ln-MOFs) for ratiometric fluorescence sensing and proton conductivity is a significant challenge.
• Existing methods for detecting UV filters and materials for proton conduction often lack selectivity or efficiency.

Purpose of the Study:

• To synthesize a novel 3D Eu-MOF using a dual-ligand strategy.
• To investigate its capability for ratiometric fluorescent detection of benzophenone-like UV filters (BP-like UVFs).
• To evaluate its proton conductivity for potential applications in energy devices.

Main Methods:

• Hydrothermal synthesis of a 3D Eu-MOF using (4-carboxypiperidyl)-N-methylenephosphonic acid and 4-sulfobenzoic acid monopotassium salt.
• Ratiometric fluorescent spectroscopy for sensing BP-like UVFs in aqueous-ethanolic solutions and urine samples.
• Proton conductivity measurements under varying temperature and humidity conditions.
• Analysis of sensing mechanisms through experimental investigations.

Main Results:

• The synthesized Eu-MOF demonstrated sensitive and selective ratiometric fluorescent detection of BP-like UVFs with low detection limits.
• The sensing mechanism involves a synergistic effect including energy transfer, internal filtration effect, complex formation, and ligand-analyte interactions.
• The Eu-MOF exhibited a proton conductivity of 2.60 × 10⁻⁴ S cm⁻¹ at 368 K and 95% relative humidity.

Conclusions:

• The developed Eu-MOF is a promising candidate for dual-functional applications in environmental sensing and proton conduction.
• The study provides a valuable framework for designing multifunctional Ln-MOFs with enhanced performance.
• A portable test paper was successfully fabricated for practical detection of UV filters.