A highly sensitive fluorescence probe for metallothioneins based on tiron-copper complex

Area of Science:

• Analytical Chemistry
• Biochemistry
• Materials Science

Background:

• Metallothioneins (MTs) are crucial proteins involved in heavy metal detoxification and oxidative stress response.
• Sensitive and selective detection methods for MTs are essential for understanding their biological roles and for toxicological assessments.
• Existing methods for MT detection can be complex or lack the required sensitivity.

Purpose of the Study:

• To develop a novel fluorescence probe for the direct and sensitive detection of metallothioneins.
• To investigate the interaction between a tiron-copper complex and metallothioneins.
• To establish an optimized method for quantifying metallothioneins at nanomolar levels.

Main Methods:

• Fabrication of a tiron-copper complex as a fluorescence probe.
• Utilizing Britton-Robinson (B-R) buffer at pH 7.50 for optimal detection.
• Measuring fluorescence enhancement at 347 nm upon interaction with metallothioneins.

Main Results:

• The interaction between the bis(tiron)copper(II) complex and metallothioneins resulted in enhanced fluorescence intensity.
• A linear relationship was observed between fluorescence intensity and metallothionein concentration (8.80 × 10⁻⁹–7.70 × 10⁻⁷ mol L⁻¹).
• The method demonstrated a low detection limit (2.60 × 10⁻⁹ mol L⁻¹), high precision (RSD 0.77%), and good recovery (94.4%).

Conclusions:

• The developed tiron-copper complex serves as a sensitive and selective fluorescence probe for metallothioneins.
• The method is reliable for determining trace levels of metallothioneins in complex biological matrices, such as fish visceral organs.
• The results show good agreement with established methods like High-Performance Liquid Chromatography (HPLC).