A General Method To Increase Stokes Shift by Introducing Alternating Vibronic Structures

Area of Science:

• Biomedical Imaging
• Organic Chemistry
• Materials Science

Background:

• Commercially available fluorescent dyes often have small Stokes shifts, leading to poor signal-to-noise ratios and self-quenching.
• Current microscopy configurations are limited by the properties of existing fluorophores, hindering advanced imaging techniques.

Purpose of the Study:

• To develop a generalizable method for significantly increasing the Stokes shifts of common fluorophores.
• To improve the imaging efficiency and photostability of existing commercial dyes.

Main Methods:

• Appending a 1,4-diethyl-decahydro-quinoxaline (DQ) moiety to the conjugated structure of fluorophores.
• Evaluating the impact of the DQ moiety on Stokes shift, emission wavelength, and photostability across 11 different fluorophores.

Main Results:

• The DQ moiety successfully expanded Stokes shifts, emission wavelength, and photostability of 11 fluorophores by over 3-fold.
• A DQ derivative of hemicyanine showed a 5-fold signal increase in mouse models compared to indocyanine green.
• DQ-modified fluorophores enabled robust cell behavior studies through one-excitation, multiple emission imaging.

Conclusions:

• The developed method offers a generalizable approach to enhance the performance of commercial fluorophores.
• DQ-modified dyes show promise for super-resolution microscopy and second window near-infrared imaging.
• This technique can significantly improve signal-to-noise ratios and reduce self-quenching in various biomedical imaging applications.