Abstrakt: |
Luminescent semiconductor quantum dots (QDs) have ideal optical properties and havebeen used to tag biomolecules for bio-detection and bio-imaging. Some efforts have beenmade to incorporate QDs into polymer microbeads in order to render them water soluble,chemically stable, and biocompatible in physiological media. While these microbeads aregenerally very useful for multiplexed immunoassays, they are not suitable for the stainingor labelling of subcellular components or intracellular measurements as they are relativelylarge in size. In this paper, we present a novel and easy way to encapsulate QDsinto chitosan nanoparticles. The nanoparticles formed are very monodisperse,spherical in shape, and about 102 nm in size with embedded QDs dispersed withinchitosan nanoparticles. The fluorescence quantum yield of the QDs in chitosanis found to be 11.8% higher than that of free QDs. In addition, as chitosan ispresent on the outermost layer of the nanoparticles, biomolecules can be furtherattached to the amine and hydroxyl groups on chitosan through chemical bonding.The QD based chitosan nanoparticles will be very useful for either multiplexedbioassays or intracellular study due to their very small sizes. Use of this approachcan be extended to the encapsulation of multiple-colour QDs and other colloidalnanocrystals. [ABSTRACT FROM AUTHOR] |