Sugar-Quantum Dot Conjugates for a Selective and Sensitive Detection of Lectins
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- 作者：Ponnusamy Babu ; Sharmistha Sinha ; Avadhesha Surolia
- 刊名：Bioconjugate Chemistry
- 出版年：2007
- 出版时间：January 2007
- 年：2007
- 卷：18
- 期：1
- 页码：146 - 151
- 全文大小：377K
- 年卷期：v.18,no.1(January 2007)
- ISSN：1520-4812
文摘
One-pot synthesized neoglycoconjugates with a reactive thiol group are introduced here for functionalizationwith carbohydrates for solubilization and stabilization of CdSe-ZnS quantum dots in aqueous solution. Threedifferent sizes of quantum dots (QDs) with lactose, melibiose, and maltotriose on their surface have been utilized,for the first time, for lectin detection through agglutination assay. The sugar-QDs thus synthesized werecharacterized by transmission election microscopy (TEM), fluorescence, and absorption spectroscopy. Agglutinationof sugar-QDs by three different lectins occurred through specific multivalent carbohydrate-lectin interactionsand was studied extensively by monitoring the scattered light at 600 nm. This assay was very selective, whichhas been demonstrated by a more selective binding of soybean agglutinin (SBA) with melibiose-QD, as comparedto lactose-QD, and specific deagglutination caused by 
-D-galactose, while -D-mannose did not show any effect.The detection sensitivity of the maltotriose-QD was tested with Concanavalin A (ConA), and as little as 100 nMof the lectin was detected using light scattering. The detection sensitivity of this protocol has been enhancedconsiderably by the fluorescence properties of QDs. This agglutination process seems to occur through formationof smaller soluble aggregates, which further associate to form larger aggregates.
-D-galactose, while -D-mannose did not show any effect.The detection sensitivity of the maltotriose-QD was tested with Concanavalin A (ConA), and as little as 100 nMof the lectin was detected using light scattering. The detection sensitivity of this protocol has been enhancedconsiderably by the fluorescence properties of QDs. This agglutination process seems to occur through formationof smaller soluble aggregates, which further associate to form larger aggregates.