A rhodamine based fluorescent probe for Hg2+ and its application to cellular imaging

Area of Science:

• Analytical Chemistry
• Environmental Science
• Biomedical Engineering

Background:

• Mercury ions (Hg2+) pose significant environmental and health risks.
• Sensitive and selective detection methods for Hg2+ are crucial for environmental monitoring and biological studies.
• Existing detection methods often face challenges in selectivity, sensitivity, or applicability in biological systems.

Purpose of the Study:

• To synthesize and characterize a new rhodamine-based fluorescent probe (Rh-F) for Hg2+ detection.
• To evaluate the probe's performance in terms of sensitivity, selectivity, and reversibility.
• To demonstrate the probe's utility for Hg2+ detection in biological samples, specifically in living cells.

Main Methods:

• Synthesis of a rhodamine-based fluorescent probe (Rh-F).
• Spectroscopic analysis (fluorescence and colorimetric) for Hg2+ detection in aqueous ethanol.
• Reversibility, linearity, and selectivity studies with various metal ions.
• Application of the probe for fluorescent imaging of Hg2+ in L-929 cells.

Main Results:

• The synthesized Rh-F probe exhibits a detectable color and fluorescence change upon binding Hg2+.
• The detection mechanism involves a ring-opening reaction and formation of a 1:1 complex, leading to enhanced fluorescence.
• The probe demonstrates a linear response in the 200nM–1000nM range with a low detection limit of 4.2nM.
• Rh-F shows high selectivity for Hg2+ over other common metal ions.
• Successful application in fluorescent imaging of intracellular Hg2+ in L-929 cells.

Conclusions:

• Rh-F is a highly selective and sensitive fluorescent probe for Hg2+ detection.
• The probe's mechanism is based on a reversible spirolactam ring-opening process.
• Rh-F is suitable for monitoring Hg2+ in living cells, offering potential for environmental and biomedical applications.