Two heterometallic MOFs fluorescence probes: Their syntheses, structures, and sensing properties

Area of Science:

• Materials Chemistry
• Coordination Chemistry
• Analytical Chemistry

Background:

• Metal-organic frameworks (MOFs) offer tunable properties for sensing applications.
• Luminescent MOFs are particularly promising for detecting specific analytes.
• Developing selective and sensitive detection methods for contaminants is crucial.

Purpose of the Study:

• Synthesize novel d-f heterometallic MOFs using a specific ligand.
• Investigate the luminescence properties of the synthesized MOFs.
• Evaluate the MOFs' capability for selective detection of palmatine and tartrazine.

Main Methods:

• Synthesis of two isomorphic d-f heterometallic MOFs: {[LnCd2(pbta)2Cl(H2O)4](H2O)4}n (Ln = Eu, Tb).
• Characterization of luminescence properties in aqueous solutions.
• Testing selectivity, recoverability, and anti-interference for palmatine and tartrazine detection.
• Elucidation of sensing mechanisms via experiments and theoretical calculations.
• Fabrication of fluorescent sensing films.

Main Results:

• Stable luminescence observed for both complexes in aqueous solution.
• Complex 1 selectively detected palmatine (PMT) in simulated urine.
• Complex 2 distinguished tartrazine (TAR) in food additives.
• High selectivity, recoverability, anti-interference, and low detection limits achieved for both analytes.
• Fluorescence mechanisms elucidated, and sensing films fabricated for visual detection.

Conclusions:

• Successfully synthesized two novel d-f heterometallic MOFs with porous 3D structures.
• Demonstrated the potential of these MOFs as highly selective and sensitive fluorescent sensors for PMT and TAR.
• The developed sensing films offer practical applications for visual identification of these compounds.