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Hydrophilic CdSe-ZnS Core-Shell Quantum Dots with Reactive Functional Groups on Their Surface

Biomedical Sciences Research Institute Computer Science Research Institute Environmental Sciences Research Institute Nanotechnology & Advanced Materials Research Institute

Yildiz, Ibrahim, Deniz, Erhan, Callan, Bridgeen, Cruickshank, Stuart F., Callan, John and Raymo, Francisco M. (2010) Hydrophilic CdSe-ZnS Core-Shell Quantum Dots with Reactive Functional Groups on Their Surface. LANGMUIR, 26 (13). pp. 11503-11511. [Journal article]

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DOI: 10.1021/la1010488

Abstract

We synthesized macromolecular ligands for CdSe-ZnS core-shell quantum dots incorporating multiple thiol groups, poly(ethylene glycol) chains, and either carboxylic acids or primary amines along a common poly(methacrylate) backbone. The thiol groups encourage the adsorption of these macromolecular constructs on the ZnS shell of the nanoparticles, and the poly(ethylene glycol) chains impose hydrophilic character on the resulting assemblies. Indeed, the coated quantum dots are readily soluble in water and are stable under these conditions for months over a broad pH range (4.0-12.0) and even in the presence of large salt concentrations. In addition, these nanoparticles have relatively small hydrodynamic diameters (17-30 nm) and good quantum yields (0.3-0.4). Furthermore, the pendant carboxylic acids or primary amines of the macromolecular ligands can be exploited to modify the quantum dots after the adsorption of the polymers on their surface. For example, boron dipyrromethene dyes can be connected to the hydrophilic quantum dots on the basis of amide bond formation to encourage the transfer of energy from the luminescent CdSe core to the organic dyes. Our hydrophilic nanoparticles can also cross the membrane of Chinese hamster ovarian cells and accumulate in the cytosol with limited nuclear localization. Moreover, the internalized quantum dots are not cytotoxic and have essentially no influence on cell viability. Thus, our strategy for the preparation of biocompatible quantum dots can evolve into the development of valuable luminescent probes with nanoscaled dimensions and optimal photophysical properties for a diversity of biomedical applications.

Item Type:Journal article
Faculties and Schools:Faculty of Life and Health Sciences
Faculty of Life and Health Sciences > School of Pharmacy and Pharmaceutical Science
Research Institutes and Groups:Biomedical Sciences Research Institute
Biomedical Sciences Research Institute > Pharmaceutical Science and Practice
ID Code:19932
Deposited By:Professor John Callan
Deposited On:13 Sep 2011 14:55
Last Modified:19 Nov 2012 15:16

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