Binuclear Lanthanide Complexes as Magnetic Resonance and Optical Imaging Probes for Redox Sensing

Area of Science:

• Inorganic Chemistry
• Chemical Biology
• Bioimaging

Background:

• Lanthanide complexes are explored for imaging and sensing.
• Redox-sensitive probes are crucial for understanding biological processes.

Purpose of the Study:

• To develop novel lanthanide(III) complexes as redox probes with dual magnetic resonance and luminescence outputs.
• To functionalize ligands with reducible groups for tunable redox responses.
• To optimize probes for specific imaging modalities like MR imaging or luminescence sensing.

Main Methods:

• Synthesis of lanthanide(III) complexes with nitro, azobenzene, and azide functionalized ligands.
• Electrochemical analysis to determine cathodic onset potentials for reduction.
• Characterization of magnetic resonance (MR) and luminescence properties.
• Evaluation of probe response under chemical and biocatalytic reductive conditions.

Main Results:

• Developed a family of lanthanide(III) complexes acting as redox probes.
• Ligand reduction to aniline triggers distinct MR and luminescence outputs.
• Optimized probes for MR imaging (Gd) and highly efficient luminescence (Tb).
• Tb(III) complexes exhibit turn-on luminescence with 45% quantum yield and millisecond lifetimes.
• Tunable redox potentials allow for discrimination of reductive conditions.

Conclusions:

• These versatile lanthanide(III) complexes offer tunable redox sensing capabilities.
• The dual-output probes enable advanced redox imaging, including hypoxic environments.
• Potential for new approaches in biological redox sensing and imaging.