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Characterization of quantum dots using capillary zone electrophoresis
- Pereira, Mark, Lai, Edward P.C., Hollebone, Bryan
- Electrophoresis 2007 v.28 no.16 pp. 2874-2881
- absorption, capillary zone electrophoresis, electrolytes, equipment, hydrodynamics, immunoassays, pH, quantum dots, sodium, sodium phosphate
- Commercially available quantum dots (QDs) were characterized using CE. The CE instruments were laboratory-built, each being capable of both electrokinetic and hydrodynamic injection. Modes of detection include UV absorption and LIF. The CE-LIF system was further modified to handle microliter sample volumes during injection. Sodium phosphate (5-25 mM, pH 7.5-11) was found to be a good buffer electrolyte. Sodium mercaptoproprionate CdTe/CdS (ADS620) QDs and carboxylic acid CdSe/ZnS (T2-Evitag) QDs yielded high separation efficiencies of N = 1.5x10⁶ plates at tM = 10 min and N = 1.0x10⁵ plates at tM = 3.8 min, respectively. Apparently the EDC/sulfo-NHS bioconjugation chemistry worked well with the neutral T2-Evitag QDs, but not so well with the negatively charged ADS620 QDs. This preliminary knowledge will serve as a basis for new CE immunoassay studies of QD-biomolecule conjugates and their immunocomplexes with target analytes.