Capillary electrophoretic separation of nanoparticles

Sławomir Oszwałdowski , Katarzyna Zawistowska-Gibuła , Kenneth P. Roberts

Abstract

In the present work, CdSe nanocrystals (NCs) synthesized with a trioctylphosphine surface passivation layer were modified using amphiphilic molecules to form a surface bilayer capable of providing stable NCs aqueous solutions. Such modified nanocrystals were used as a test solute in order to analyze new electrophoretic phenomena, by applying a micellar plug as a separation tool for discriminating nanocrystals between micellar and micelle-free zones during electrophoresis. The distribution of NCs between both zones depended on the affinity of nanocrystals towards the micellar zone, and this relies on the kind of surface ligands attached to the NCs, as well as electrophoretic conditions applied. In this case, the NCs that migrated within a micellar zone can be focused using a preconcentration mechanism. By modifying electrophoretic conditions, NCs were forced to migrate outside the micellar zone in the form of a typical CZE peak. In this situation, a two-order difference in separation efficiencies, in terms of theoretical plates, was observed between focused NCs (N \\textasciitilde\ 107) and a typical CZE peak for NCs (N \\textasciitilde\ 105). By applying the amino-functionalized NCs the preconcentration of NCs, using a micellar plug, was examined, with the conclusion that preconcentration efficiency, in terms of the enhancement factor for peak height (SEFheight) can be, at least 20. The distribution effect was applied to separate CdSe/ZnS NCs encapsulated in silica, as well as surface-modified with DNA, which allows the estimation of the yield of conjugation of biologically active molecules to a particle surface. Figure Micellar plug as a tool to separate nanoparticles: nanocrystals coated with an ionic surfactant form a pseudomicellar system with a non-ionic surfactant. Appling this system in the form of a plug, in capillary electrophoresis, nanocrystals preconcentration within a plug or release from a plug, depending on applied conditions, were observed. This was used to discriminate particles vs. particles bioconjugated with aptamer
Author Sławomir Oszwałdowski (FC / CAC)
Sławomir Oszwałdowski,,
- Chair Of Analytical Chemistry
, Katarzyna Zawistowska-Gibuła - [Warsaw University of Technology (PW), MNiSW [80]]
Katarzyna Zawistowska-Gibuła,,
-
- Politechnika Warszawska
, Kenneth P. Roberts - [University of Tulsa]
Kenneth P. Roberts,,
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Journal seriesAnalytical and Bioanalytical Chemistry, ISSN 1618-2642, 1618-2650, (0 pkt)
Issue year2011
Vol399
No8
Pages2831-2842
Keywords in EnglishAnalytical Chemistry, Biochemistry, general, Capillary electrophoresis, Environmental Monitoring/Analysis, Focusing, Food Science, Laboratory Medicine, Measurement Science and Instrumentation, Micelles, Nanocrystals, Oligomer
DOIDOI:10.1007/s00216-011-4650-y
URL http://link.springer.com/article/10.1007/s00216-011-4650-y
Score (nominal)0
Score sourcejournalList
Publication indicators Scopus Citations = 25; WoS Citations = 24
Citation count*23 (2016-05-30)
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* presented citation count is obtained through Internet information analysis and it is close to the number calculated by the Publish or Perish system.
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