Chemical Control of Fluorescence Lifetime towards Multiplexing Imaging

Area of Science:

• Chemical Biology
• Biomedical Imaging
• Spectroscopy

Background:

• Fluorescence lifetime imaging (FLIM) is crucial in biomedical research.
• Multiplexing imaging expands FLIM capabilities using probes with distinct excited-state lifetimes.
• Controlling fluorescence lifetimes of probes remains a significant challenge.

Purpose of the Study:

• To provide chemical strategies for regulating the fluorescence lifetime of boron dipyrromethene (BODIPY) derivatives.
• To establish principles for rational control of fluorescence lifetimes in small molecule fluorophores.
• To develop BODIPY probes for multiplexing imaging applications.

Main Methods:

• Utilized boron dipyrromethene (BODIPY) as a model system.
• Investigated the effect of substituent electronegativity at the 8' and 5' positions on fluorescence lifetime.
• Analyzed mechanisms including photo-induced electron transfer (PET) and intramolecular charge transfer (ICT).

Main Results:

• Electronegativity of substituents at the 8' and 5' positions significantly impacts fluorescence lifetime for green and red-emitting BODIPY scaffolds.
• PET and ICT processes were identified as key mechanisms influencing fluorescence lifetime at the 8' and 5' positions, respectively.
• Generated novel BODIPY probes enabling target separation in imaging experiments via fluorescence lifetime signals.

Conclusions:

• Rational control of fluorescence lifetime is achievable through strategic chemical modifications, particularly by modulating substituent electronegativity.
• The findings provide a feasible strategy for developing new small molecule fluorophores with tunable fluorescence lifetimes.
• This work advances multiplexing imaging capabilities by enabling the separation of multiple targets based on distinct fluorescence lifetimes.