title: Infrared emitting quantum dots: DNA conjugation and DNA origami directed self-assembly.
abstract: QDs that emit in the infrared (IR) range are of special interest at the moment because of their potential as tissue imaging reagents. Due to autofluorescence from tissues, QDs that emit in the visible range fail to produce good signal to noise ratios. Here we report the production of Cd(x)Pb(1-x)Te tertiary-alloyed QDs that emit in the 1100-1300 nm wavelength range, capped with the hydrophilic ligands mercaptopropionic acid (MPA) or glutathione (GSH), together with DNA, as specific surface tags. We observed an interesting dependence of the QD emission peaks on the species of capping ligand used. ICP-MS analysis confirmed that changing the identity of the surface ligand in the reaction mixture shifted the elemental composition of the particles and resulted in different Cd/Pb ratios. Further, DNA directed assembly of the particles onto DNA nanostructures ensures that the particle remains stable in high salt conditions, which is crucial to biological applications.
authors.affiliation: Department of Chemistry and Biochemistry, Center for Single Molecule Biophysics, Biodesign Institute at Arizona State University, 1001 South McAllister Avenue, Tempe, Arizona 85287-5601, USA. yan_liu@asu.edu.
authors.forename: Anirban
authors.initials: A
authors.lastname: Samanta
authors.forename: Zhengtao
authors.initials: Z
authors.lastname: Deng
authors.forename: Yan
authors.initials: Y
authors.lastname: Liu
mesh_terms: D002104:Cadmium / Q000737:chemistry; D004247:DNA / Q000737:chemistry*; D005978:Glutathione / Q000737:chemistry; D007854:Lead / Q000737:chemistry; D008024:Ligands; D018625:Microscopy, Atomic Force; D045663:Quantum Dots / Q000737:chemistry*; D013055:Spectrophotometry, Infrared
chemical_list: D008024:Ligands; D002104:Cadmium; D007854:Lead; D004247:DNA; D005978:Glutathione