Dimerization-Enhanced Excimer Probe for Wash-Free Plasma Membrane Fluorescence Imaging.

Area of Science:

• Chemical Biology
• Biophysical Chemistry

Background:

• Excimer probes offer advantages over monomeric fluorophores in bioimaging due to red-shifted spectra and larger Stokes shifts.
• Developing targeted, sensitive fluorescent probes is crucial for advancing cellular imaging techniques.

Purpose of the Study:

• To design and synthesize a novel excimer-forming, membrane-targeting fluorogenic probe (DIPP).
• To evaluate the photophysical properties and bioimaging capabilities of DIPP.

Main Methods:

• Covalent conjugation of two triphenylimidazole moieties via a 1,5-bis(pyridin-1-yl)pentane linker to create DIPP.
• Spectroscopic analysis in various organic solvents and aqueous solutions with SDS micelles.
• Cellular internalization and imaging studies to assess probe performance.

Main Results:

• DIPP exhibited exclusive excimer fluorescence in most organic solvents, with dual emission in DMSO.
• Negligible fluorescence in aqueous solution, with significantly enhanced excimer emission in SDS micelles.
• DIPP demonstrated bright red emission (>610 nm), a large Stokes shift (>210 nm), rapid cellular uptake (~5 min), and low cytotoxicity.

Conclusions:

• DIPP is an effective membrane-targeting fluorescent probe leveraging environmentally sensitive excimer formation.
• The probe's properties are advantageous for wash-free, real-time bioimaging applications.
• DIPP shows significant potential for advanced cellular and membrane imaging.