A simple and selective fluorometric assay for dopamine using a calcein blue-Fe2+ complex fluorophore

Area of Science:

• Analytical Chemistry
• Biochemistry
• Chemical Sensing

Background:

• Dopamine is a crucial neurotransmitter involved in various physiological processes.
• Accurate quantification of dopamine is essential for diagnosing and monitoring neurological disorders.
• Existing dopamine detection methods can be complex, expensive, or lack selectivity.

Purpose of the Study:

• To develop a novel, sensitive, and selective fluorimetric assay for dopamine detection.
• To utilize a calcein blue-Fe(2+) complex as a chemical sensor for dopamine.
• To establish a cost-effective and straightforward alternative to conventional dopamine assays.

Main Methods:

• A fluorimetric assay was designed using calcein blue (CB) complexed with Fe(2+) ions.
• The fluorescence quenching of the CB-Fe(2+) complex by Fe(2+) was exploited.
• Ligand exchange reactions upon dopamine addition led to fluorescence recovery, enabling dopamine quantification.

Main Results:

• Fluorescence intensity at 440 nm (excitation 340 nm) showed a linear correlation with dopamine concentration.
• The assay demonstrated good selectivity for dopamine over other catecholamines.
• The working range was 50 μM to 1 mM, with a limit of detection around 10 μM.

Conclusions:

• The developed fluorimetric assay provides a simple, economical, and selective method for dopamine determination.
• This assay offers a viable alternative to traditional methods like ELISA for dopamine quantification.
• The assay's sensitivity and selectivity make it suitable for various analytical applications.