COLL 249 |
| Colloidal nanocrystals have great importance in basic and applied research. We have synthesized a water-soluble amino acid based polyaspartic acid with cystein or methionine on its backbone with an average molecular weight of 10,000-15,000. This polymer was used as capping ligand for gold, silver and ZnS-capped CdSe nanoparticles. Polymer-coated water-soluble nanoparticles were synthesized by ligand-exchange method from near-monodisperse, hydrophobic Au and Ag nanoparticles and ZnS-capped CdSe quantum dots (QDs) prepared in organic solvents. Multiple thiol groups in the polymer backbone offered excellent protection of the nanoparticles against aggregation, while the carboxylic acid groups provided the possibility of covalent binding with antibody. Compared to the conventional thiol-based ligands, the polymer coating led to superior colloidal stability under experimental conditions involved in bioconjugation and purification steps. Anti-human IgG (anti-h-IgG) and anti-mouse EGFR (anti-m-EGFR) antibodies were conjugated with the polymer-coated nanoparticles, and successfully applied towards protein detection. This polymer coating exhibited minimal non-specific interaction with cells, and can be broadly applied for cell labeling.
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Fundamental Research in Colloid and Surface Chemistry
6:00 PM-8:00 PM, Monday, August 20, 2007 BCEC -- East Registration, Poster
Division of Colloid & Surface Chemistry |