Open AccessMinimization of self‐quenching fluorescence on dyes conjugated to biomolecules with multiple labeling sites via asymmetrically charged NIR fluorophores
Author(s) -
Zhegalova Natalia G.,
He Shawn,
Zhou Haiying,
Kim David M.,
Berezin Mikhail Y.
Publication year - 2014
Publication title -
contrast media & molecular imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.714
H-Index - 50
eISSN - 1555-4317
pISSN - 1555-4309
DOI - 10.1002/cmmi.1585
Subject(s) - cyanine , fluorescence , chromophore , photochemistry , chemistry , quenching (fluorescence) , conjugated system , stacking , biomolecule , absorption (acoustics) , materials science , organic chemistry , optics , polymer , biochemistry , physics , composite material
Self‐aggregation of dyes even at low concentrations poses a considerable challenge in preparing sufficiently bright molecular probes for in vivo imaging, particularly in the conjugation of near infrared cyanine dyes to polypeptides with multiple labeling sites. Such self‐aggregation leads to a significant energy transfer between the dyes, resulting in severe quenching and low brightness of the targeted probe. To address this problem, we designed a novel type of dye with an asymmetrical distribution of charge. Asymmetrical distribution prevents the chromophores from π ‐stacking thus minimizing the energy transfer and fluorescence quenching. The conjugation of the dye to polypeptides showed only a small presence of an H‐aggregate band in the absorption spectra and, hence, a relatively high quantum efficiency. Copyright © 2014 John Wiley & Sons, Ltd.