title: Sorting fluorescent nanocrystals with DNA.
abstract: Semiconductor nanocrystals with narrow and tunable fluorescence are covalently linked to oligonucleotides. These biocompounds retain the properties of both nanocrystals and DNA. Therefore, different sequences of DNA can be coded with nanocrystals and still preserve their ability to hybridize to their complements. We report the case where four different sequences of DNA are linked to four nanocrystal samples having different colors of emission in the range of 530-640 nm. When the DNA-nanocrystal conjugates are mixed together, it is possible to sort each type of nanoparticle by using hybridization on a defined micrometer-size surface containing the complementary oligonucleotide. Detection of sorting requires only a single excitation source and an epifluorescence microscope. The possibility of directing fluorescent nanocrystals toward specific biological targets and detecting them, combined with their superior photostability compared to organic dyes, opens the way to improved biolabeling experiments, such as gene mapping on a nanometer scale or multicolor microarray analysis.
authors.affiliation: Department of Chemistry, University of California, Berkeley, California 94720, USA. gerion@uclink4.berkeley.edu
authors.forename: Daniele
authors.initials: D
authors.lastname: Gerion
authors.forename: Wolfgang J
authors.initials: WJ
authors.lastname: Parak
authors.forename: Shara C
authors.initials: SC
authors.lastname: Williams
authors.forename: Daniela
authors.initials: D
authors.lastname: Zanchet
authors.forename: Christine M
authors.initials: CM
authors.lastname: Micheel
authors.forename: A Paul
authors.initials: AP
authors.lastname: Alivisatos
mesh_terms: D004247:DNA / Q000737:chemistry* / Q000235:genetics; D005456:Fluorescent Dyes / Q000737:chemistry*; D006046:Gold / Q000737:chemistry; D036103:Nanotechnology / Q000379:methods; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods; D012666:Semiconductors; D012822:Silicon Dioxide / Q000737:chemistry
chemical_list: D005456:Fluorescent Dyes; D006046:Gold; D012822:Silicon Dioxide; D004247:DNA