TY - JOUR
T1 - Preparative size-exclusion chromatography for purification and characterization of colloidal quantum dots bound by chromophore-labeled polymers and low-molecular-weight chromophores
AU - Wang, Mingfeng
AU - Bardajee, Ghasem Rezanejade
AU - Kumar, Sandeep
AU - Nitz, Mark
AU - Scholes, Gregory D.
AU - Winnik, Mitchell A.
N1 - Funding Information:
The authors thank NSERC Canada for their financial support and Dr. M. Hines at Evident Technologies for providing the CdSe/ZnS sample. We also thank Anna Valborg Gudmundsdottir and Dr. Guohua Zhang for the help with the HPLC experiments.
PY - 2009/6/19
Y1 - 2009/6/19
N2 - We explore the use of preparative size-exclusion chromatography (SEC) and high-performance liquid chromatography (HPLC) to purify quantum dots (QDs) after surface modification. In one example, in which Bio-Beads (S-X1) were used as the packing material for the preparative SEC column, CdSe QDs treated with a functional coumarin dye could be separated from the excess free dye by using tetrahydrofuran (THF) as the mobile phase. This column was unable to separate polymer-coated QDs from free polymer (M ∼ 8000) because of the relatively low cutoff mass of the column. Here a preparative HPLC column packed with TOYOPEARL gel allowed the effective separation of polymer-bound QDs from the excess free polymer by using N-methyl-2-pyrrolidinone (NMP) as the mobile phase. When other solvents such as absolute ethanol, acetonitrile, THF, and THF-triethylamine mixtures were used as the eluent, QDs stuck to the column. While NMP was an effective medium to remove excess free polymer from the QDs, it was difficult to transfer the purified QDs to more volatile solvents and maintain colloidal stability.
AB - We explore the use of preparative size-exclusion chromatography (SEC) and high-performance liquid chromatography (HPLC) to purify quantum dots (QDs) after surface modification. In one example, in which Bio-Beads (S-X1) were used as the packing material for the preparative SEC column, CdSe QDs treated with a functional coumarin dye could be separated from the excess free dye by using tetrahydrofuran (THF) as the mobile phase. This column was unable to separate polymer-coated QDs from free polymer (M ∼ 8000) because of the relatively low cutoff mass of the column. Here a preparative HPLC column packed with TOYOPEARL gel allowed the effective separation of polymer-bound QDs from the excess free polymer by using N-methyl-2-pyrrolidinone (NMP) as the mobile phase. When other solvents such as absolute ethanol, acetonitrile, THF, and THF-triethylamine mixtures were used as the eluent, QDs stuck to the column. While NMP was an effective medium to remove excess free polymer from the QDs, it was difficult to transfer the purified QDs to more volatile solvents and maintain colloidal stability.
KW - Chromophores
KW - High-performance liquid chromatography
KW - Polymers
KW - Quantum dots
KW - Size-exclusion chromatography
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U2 - 10.1016/j.chroma.2009.04.060
DO - 10.1016/j.chroma.2009.04.060
M3 - Article
C2 - 19446821
AN - SCOPUS:65649124226
SN - 0021-9673
VL - 1216
SP - 5011
EP - 5019
JO - Journal of Chromatography A
JF - Journal of Chromatography A
IS - 25
ER -