Reversible and Sensitive Hg²⁺ Detection by a Cell-Permeable Ytterbium Complex.

Area of Science:

• Inorganic Chemistry
• Analytical Chemistry
• Materials Science

Background:

• Mercury (Hg²⁺) is a toxic heavy metal pollutant.
• Developing sensitive and selective detection methods for Hg²⁺ is crucial for environmental and health monitoring.
• Lanthanide complexes offer unique luminescent properties for sensing applications.

Purpose of the Study:

• To develop a cell-permeable ytterbium complex for sensitive and reversible detection of mercury ions (Hg²⁺).
• To investigate the sensing mechanism based on fluorescence resonance energy transfer (FRET) and the lanthanide antenna effect.
• To elucidate the binding mechanism of the ytterbium complex with Hg²⁺.

Main Methods:

• Synthesis and characterization of a cell-permeable ytterbium complex.
• Detection of Hg²⁺ in aqueous solution using visible and near-infrared (NIR) emission.
• Investigation of the sensing mechanism using FRET and the lanthanide antenna effect.
• Nuclear Magnetic Resonance (NMR) spectroscopy and Density Functional Theory (DFT) calculations to study the binding mechanism.

Main Results:

• The ytterbium complex demonstrated reversible binding with Hg²⁺ in aqueous solution.
• An "off-on" visible and NIR emission response was observed upon Hg²⁺ binding.
• The detection method exhibited a fast response time and a sensitivity of 150 nM for Hg²⁺.
• NMR and DFT calculations provided insights into the binding mechanism.

Conclusions:

• The developed ytterbium complex is a promising sensor for reversible and sensitive Hg²⁺ detection.
• The combination of FRET and the lanthanide antenna effect enables efficient signal transduction.
• The study provides a mechanistic understanding of the Hg²⁺ binding process.