10.1021/acs.bioconjchem.5b00048.s001
Jay W. Grate
Jay W.
Grate
Kai-For Mo
Kai-For
Mo
Yongsoon Shin
Yongsoon
Shin
Andreas Vasdekis
Andreas
Vasdekis
Marvin G. Warner
Marvin G.
Warner
Ryan T. Kelly
Ryan T.
Kelly
Galya Orr
Galya
Orr
Dehong Hu
Dehong
Hu
Karl J. Dehoff
Karl J.
Dehoff
Fred J. Brockman
Fred J.
Brockman
Michael J. Wilkins
Michael J.
Wilkins
Alexa Fluor-Labeled Fluorescent Cellulose Nanocrystals
for Bioimaging Solid Cellulose in Spatially Structured Microenvironments
American Chemical Society
2015
bind Alexa Fluor dyes
oxidizing vicinal diols
Reductive amination reactions
Alexa Fluor dye
Spatially Structured MicroenvironmentsMethods
pore network microfluidic structures
cellulose deposits
Fluorescent cellulose nanocrystals
model cellulose materials
Alexa Fluor 546
covalently conjugate Alexa Fluor dyes
PDMS
Alexa Fluor dyes
reductive step
molecule fluorescence microscopy
linker section
cellulose nanocrystals
2015-03-18 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Alexa_Fluor_Labeled_Fluorescent_Cellulose_Nanocrystals_for_Bioimaging_Solid_Cellulose_in_Spatially_Structured_Microenvironments/2185126
Methods to covalently conjugate Alexa
Fluor dyes to cellulose nanocrystals,
at limiting amounts that retain the overall structure of the nanocrystals
as model cellulose materials, were developed using two approaches.
In the first, aldehyde groups are created on the cellulose surfaces
by reaction with limiting amounts of sodium periodate, a reaction
well-known for oxidizing vicinal diols to create dialdehyde structures.
Reductive amination reactions were then applied to bind Alexa Fluor
dyes with terminal amino-groups on the linker section. In the absence
of the reductive step, dye washes out of the nanocrystal suspension,
whereas with the reductive step, a colored product is obtained with
the characteristic spectral bands of the conjugated dye. In the second
approach, Alexa Fluor dyes were modified to contain chloro-substituted
triazine ring at the end of the linker section. These modified dyes
then were reacted with cellulose nanocrystals in acetonitrile at elevated
temperature, again isolating material with the characteristic spectral
bands of the Alexa Fluor dye. Reactions with Alexa Fluor 546 are given
as detailed examples, labeling on the order of 1% of the total glucopyranose
rings of the cellulose nanocrystals at dye loadings of ca. 5 μg/mg
cellulose. Fluorescent cellulose nanocrystals were deposited in pore
network microfluidic structures (PDMS) and proof-of-principle bioimaging
experiments showed that the spatial localization of the solid cellulose
deposits could be determined, and their disappearance under the action
of Celluclast enzymes or microbes could be observed over time. In
addition, single molecule fluorescence microscopy was demonstrated
as a method to follow the disappearance of solid cellulose deposits
over time, following the decrease in the number of single blinking
dye molecules with time instead of fluorescent intensity.