Functional quantum-dot/dendrimer nanotubes for sensitive detection of DNA hybridization

The design and the fabrication of quantum dots or dendrimer composite nanotubes inside anodic aluminum oxide (AAO) membranes with a pore diameter of 400 nm and a lattice constant of 500 nm are discussed. The arrays of aligned quantum dots or dendrimer composite nanotubes enable the detection of DNA hybridization with significantly enhanced sensitivity. The emission from dye-labeled target DNA is probed with exceptionally high sensitivity and selectivity after its hybridization to the probe DNA. The QD or dendrimer composite NTs are released by selectively etching the AAO matrix with a 30 percent aqueous KOH solution at room temperature. The PL intensity of the Cy5 signal significantly decreases as the distance between the chromophores and the QD layer at the inner surface of the NT increases with an increased number of nucleotides. The NTs containing cascaded energy-transfer architectures is potentially used to spatially control the deposition of a variety of biomolecules, as required in genomic arrays.