Minimization of self‐quenching fluorescence on dyes conjugated to biomolecules with multiple labeling sites via asymmetrically charged NIR fluorophores

Abstract

Self-aggregation of dyes even at low concentrations pose 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.

Near-infrared labeled, ovalbumin loaded polymeric nanoparticles based on a hydrophilic polyester as model vaccine: In vivo tracking and evaluation of antigen-specific CD8 + T cell immune response

“…N ¼ 3 samples per condition, representative graph of 5 independent experiments. stacking of the dye at high concentrations [79]. Hydration of the NPs and a decreased stacking of NPs at the injection site during the first day would relieve the IR680 dye from both these quenching effects.…”

Photophysical Characterization and BSA Interaction of Direct Ring Carboxy Functionalized Symmetrical squaraine Dyes

“…FAB-mass (measured 326.1066; calculated 326.1057) confirms the successful synthesis of the compound [15].…”

Temperature-dependent shape-responsive fluorescent nanospheres for image-guided drug delivery

“…19 A steady state 740 nm NanoLED was used for excitation, with emission measured at 790 nm. Samples of nanospheres were diluted with water to absorbance 0.3 au measured by the spectrophotometer DU-640 (Beckman-Coulter).…”