Elongated semiconductor nanocrystals as fluorescent probes for PCR

J. Niehaus, T. Jochum, K. Werner, H. Weller
Center for Applied Nanotechnology (CAN) GmbH, DE

Keywords: quantum dots, dotrods, PCR

Summary:

We present a synthesis able to produce high quality nanorods with tunable emission colors in a reproducible way using a microfluidic continuous flow reactor. To use them as a fluorescent probe we developed a two step concept for phase transfer of NPs soluble in non-polar media. The first step is an exchange of the stabilizing organic molecules against a multidental binding short chain polymer. In a second step the modified NPs are encapsulated in block-copolymer micelles and transferred into an aqueous solution. Finally we close the micelle shell by cross linking the polymer chains to ensure a good separation of NPs and surrounding media. All this is done in a microfluidic continuous flow approach, too. Amino groups at the outer sphere of the micelle can be used to functionalize our particles with affinity molecules. We will show that it is possible to encapsulate CdSe/CdS nanorods without a loss of quantum efficiency. These nanocapsules are afterwards linked to DNA molecules via their amino groups. Hybridisation and band shift assays will be shown to prove the coupling of the nanoparticle to the DNA. These constructs can be used as fluorescent probes in PCR reactions. Results of these experiments will be shown.