Ensemble and single particle fluorescence characterization of dye-labeled cellulose nanocrystals

From National Research Council Canada

Download
  1. (PDF, 1 MB)
  2. (PDF, 506 KB)
DOIResolve DOI: http://doi.org/10.1021/acs.langmuir.7b01717
AuthorSearch for: 1 ; Search for: 1 ; Search for: 1 ; Search for: ; Search for: 1 
Name affiliation
  1. National Research Council Canada. Measurement Science and Standards
TypeArticle
Journal titleLangmuir
ISSN0743-7463
1520-5827
Volume33
Issue32
Pages8002–8011
Abstract
Cellulose nanocrystals (CNCs) have been covalently labeled with both fluorescein and rhodamine and studied by a combination of UV–vis absorption spectroscopy and ensemble and single molecule fluorescence spectroscopy. For all samples, the fluorescence anisotropy and lifetimes were consistent with effects expected for covalently bound dye molecules. Low dye loading levels (∼0.1 dye/particle) were estimated for the fluorescein-labeled CNC which coupled with the strong pH dependence make this a less suitable fluorophore for most applications. Rhodamine-labeled CNCs were prepared from both sulfated and carboxylated CNCs and had loading levels that varied from 0.25 to ∼15 dye molecules/CNC. For the sulfated samples, the absorption due to (nonfluorescent) dimeric dye increased with dye loading; in contrast, the carboxylated sample, which had the highest rhodamine content, had a low dimer yield. Single particle fluorescence studies for two of the rhodamine-labeled CNCs demonstrated that individual particles are readily detected by their stepwise blinking/bleaching behavior and by polarization effects. Overall, the results indicate the importance of understanding the effects of loading on dye photophysics to select an optimal dye concentration to maximize sensitivity while minimizing the effect of the dye on the CNC behavior. The results also demonstrate that CNCs with relatively low dye loadings (e.g., ∼1 dye/particle) are readily detectable by fluorescence and should be adequate for use in fluorescence-based biological assays or to probe the distribution of CNCs in composite materials.
Publication date
PublisherAmerican Chemical Society
LanguageEnglish
Peer reviewedYes
NPARC number23002345
Export citationExport as RIS
Report a correctionReport a correction
Record identifiera259497f-3a90-434f-bf8d-5328e444e29e
Record created2017-10-20
Record modified2017-10-20
Date modified:
Report a problem on this page