Optical Sensors Using Solvatochromic Metal-Organic Frameworks.

Area of Science:

• Materials Science
• Chemistry
• Nanotechnology

Background:

• Metal-organic frameworks (MOFs) offer tunable properties for various applications.
• Post-synthetic modification (PSM) is a powerful strategy to create novel MOF structures.
• DUT-71, a known MOF, serves as a precursor for new material synthesis.

Purpose of the Study:

• To synthesize new copper-based MOFs via PSM of DUT-71.
• To characterize the structure and properties of the resulting MOFs.
• To investigate the potential of these MOFs for analyte detection based on spectral changes.

Main Methods:

• Post-synthetic modification of DUT-71 using nitrogen-containing ligands.
• Synchrotron X-ray single-crystal diffraction for structure determination.
• Solid-state UV/Vis spectroscopy for analyzing responses to analytes.

Main Results:

• Four new MOFs (DUT-74, DUT-95, DUT-112, DUT-114) were successfully synthesized.
• The crystal structures of DUT-112 and DUT-114 were determined, revealing tetragonal symmetry.
• All synthesized MOFs exhibited distinct shifts in UV/Vis absorption spectra upon exposure to various analytes.
• The MOFs demonstrated the ability to differentiate between solvents of varying polarity.
• Detection of polar analytes at concentrations as low as 0.01 wt % in less polar solvents was achieved.

Conclusions:

• The synthesized MOFs are effective sensory materials for detecting analytes.
• The observed spectral shifts correlate with analyte polarity, enabling selective detection.
• These MOFs show promise for sensitive and selective chemical sensing applications.