Devising Efficient Red-Shifting Strategies for Bioimaging: A Generalizable Donor-Acceptor Fluorophore Prototype.

Area of Science:

• Biophotonics and Imaging
• Fluorescent Probe Development
• Spectroscopy and Computational Chemistry

Background:

• Fluorescent probes with long emission wavelengths, high fluorescence quantum yields (FQYs), and large Stokes shifts are crucial for biological imaging.
• Current fluorescent probe development is often inefficient and relies on trial-and-error.
• Achieving far-red/near-infrared emission typically requires extended conjugation, often leading to reduced fluorescence.

Purpose of the Study:

• To discuss an effective red-shifting strategy for fluorescent probes.
• To present an alternative to conventional intramolecular charge transfer (ICT) strategies for achieving redder emission.
• To explore advancements in noncanonical fluorescent protein design and generalization to other fluorophore scaffolds.

Main Methods:

• A novel red-shifting strategy based on the green fluorescent protein chromophore.
• Synergistic tuning of electronic ground and excited states.
• Spectroscopy and computation-aided design principles.

Main Results:

• The proposed strategy enables efficient red-shifting of emission wavelengths.
• It preserves or enhances desirable properties like high fluorescence quantum yields (FQYs).
• This approach offers a potentially shorter path to redder emission compared to ICT strategies.

Conclusions:

• The discussed strategy provides an efficient route to develop advanced fluorescent probes.
• This method can accelerate the design of noncanonical fluorescent proteins and other fluorophores.
• It holds promise for creating superior probes for biological imaging with enhanced red/near-infrared emission.