A Luminescent Sensor for Trace Uranyl in Nature Water Systems Using a Terbium(III)-Organic Framework

Area of Science:

• Materials Science
• Environmental Chemistry
• Analytical Chemistry

Background:

• Uranyl ions (UO2^2+) pose environmental and health risks.
• Accurate detection of uranyl ions in complex water matrices is challenging.
• Metal-organic frameworks (MOFs) offer tunable properties for sensing applications.

Purpose of the Study:

• To synthesize and characterize a novel terbium(III)-organic framework for uranyl ion detection.
• To evaluate the sensing performance of the framework in complex natural water systems.
• To elucidate the sensing mechanism using spectroscopic and computational methods.

Main Methods:

• Hydrothermal synthesis of the terbium(III)-organic framework (1).
• Uranyl ion sensing experiments in lake water and seawater.
• Fourier-transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) analyses.
• Density functional theory (DFT) calculations.

Main Results:

• The terbium(III)-organic framework (1) was successfully synthesized.
• Framework 1 exhibited high sensitivity (Ksv = 1.13 × 10^5 M^-1) and ultralow LOD (17.47 nM) for uranyl ions.
• Uranyl ions coordinated with free carboxylate groups, and photoelectron transfer caused luminescence quenching.

Conclusions:

• The synthesized terbium(III)-organic framework is a promising material for sensitive and selective uranyl ion detection.
• The material demonstrates excellent performance in complex natural water environments.
• Understanding the sensing mechanism provides insights for designing advanced uranyl sensors.