Microwave-assisted synthesis for a highly selective rhodamine 6G-derived fluorescent sensor and bioimaging

Area of Science:

• Organic Chemistry
• Analytical Chemistry
• Biophysical Chemistry

Background:

• Rhodamine derivatives are widely used as fluorescent probes.
• Selective detection of copper ions (Cu2+) is crucial in environmental and biological monitoring.
• Development of sensitive and selective chemosensors for metal ions remains an active research area.

Purpose of the Study:

• To synthesize a new rhodamine 6G derivative (R1) for selective Cu2+ sensing.
• To investigate the sensing mechanism and performance of R1 for Cu2+ detection.
• To evaluate the applicability of R1 as a fluorescent probe in biological imaging.

Main Methods:

• Microwave-assisted synthesis of rhodamine 6G derivative R1.
• Spectrophotometric and fluorometric studies for Cu2+ sensing.
• Job's plot analysis to determine binding stoichiometry.
• Cellular imaging experiments using R1 for Cu2+ detection.

Main Results:

• The synthesized R1 selectively senses Cu2+ in CH3CN/H2O solution with a visible color change and fluorescence enhancement.
• Coordination with Cu2+ opens the spirolactam ring of R1, leading to a highly fluorescent complex.
• A 1:2 binding stoichiometry between Cu2+ and R1 was confirmed by Job's plot analysis.
• The limit of detection for Cu2+ was found to be 1.23 μM.
• R1 was successfully applied for fluorescent imaging of Cu2+ in living cells.

Conclusions:

• The novel rhodamine 6G derivative R1 functions as an effective and selective chemosensor for Cu2+.
• R1 exhibits favorable photophysical properties for Cu2+ detection and imaging.
• The sensor demonstrates potential for practical applications in biological and environmental analysis of copper ions.