Minimization of self-quenching fluorescence on dyes conjugated to biomolecules with multiple labeling sites via asymmetrically charged NIR fluorophores.
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.
Department of Radiology, Washington University School of Medicine in St Louis, St Louis, MO, 63110, USA.
Natalia G
NG
Zhegalova
Shawn
S
He
Haiying
H
Zhou
David M
DM
Kim
Mikhail Y
MY
Berezin
D003287:Contrast Media / Q000737:chemistry*; D003952:Diagnostic Imaging; D005456:Fluorescent Dyes / Q000737:chemistry*; D006801:Humans; D015335:Molecular Probes / Q000737:chemistry*; D019265:Spectroscopy, Near-Infrared
D003287:Contrast Media; D005456:Fluorescent Dyes; D015335:Molecular Probes
NIR fluorescence; antibody; labeling; optical probe; quenching