A Cd(II) post-modified hydrogen-bonded organic framework toward sensitive uranyl ion detection via turn-off...

Area of Science:

• Materials Science
• Environmental Chemistry
• Analytical Chemistry

Background:

• Uranyl ion (UO22+) poses environmental and health risks, necessitating sensitive detection methods.
• Existing detection techniques may lack speed, cost-effectiveness, or sensitivity.
• Hydrogen-bonded organic frameworks (HOFs) offer potential as sensing platforms.

Purpose of the Study:

• To develop a novel fluorescent sensor for the selective and sensitive detection of uranyl ions (UO22+).
• To utilize a post-synthetic metal modification strategy on HOFs for enhanced sensing capabilities.
• To investigate the sensing mechanism and validate the method in real-world water samples.

Main Methods:

• Synthesis and characterization of a cadmium-post-modified HOF (H4-CDI-Cd).
• Fluorescence spectroscopy to evaluate the sensor's response to UO22+.
• Density Functional Theory (DFT) calculations to elucidate the binding mechanism.
• Application of the sensor to analyze UO22+ in environmental water samples.

Main Results:

• The H4-CDI-Cd sensor demonstrated selective and rapid fluorescence response to UO22+.
• Achieved a low detection limit of 19.54 nM with a linear range from 75 nM to 1 μM.
• DFT calculations confirmed Cd2+ coordination enhances UO22+ binding affinity and selectivity.
• Successful quantitative detection of UO22+ in lake water and mining wastewater samples with high recovery rates.

Conclusions:

• Post-synthetic modification of HOFs with cadmium is an effective strategy for developing sensitive uranyl ion sensors.
• The developed fluorescent sensor offers a promising tool for environmental monitoring of UO22+.
• This work highlights the potential of engineered HOFs for selective analyte detection.