title: Robust DNA-functionalized core/shell quantum dots with fluorescent emission spanning from UV-vis to near-IR and compatible with DNA-directed self-assembly.
abstract: The assembly and isolation of DNA oligonucleotide-functionalized gold nanoparticles (AuNPs) has become a well-developed technology that is based on the strong bonding interactions between gold and thiolated DNA. However, achieving DNA-functionalized semiconductor quantum dots (QDs) that are robust enough to withstand precipitation at high temperature and ionic strength through simple attachment of modified DNA to the QD surface remains a challenge. We report the synthesis of stable core/shell (1-20 monolayers) QD-DNA conjugates in which the end of the phosphorothiolated oligonucleotide (5-10 nucleotides) is "embedded" within the shell of the QD. These reliable QD-DNA conjugates exhibit excellent chemical and photonic stability, colloidal stability over a wide pH range (4-12) and at high salt concentrations (>100 mM Na(+) or Mg(2+)), bright fluorescence emission with quantum yields of up to 70%, and broad spectral tunability with emission ranging from the UV to the NIR (360-800 nm).
authors.affiliation: The Biodesign Institute and Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287, USA.
authors.forename: Zhengtao
authors.initials: Z
authors.lastname: Deng
authors.forename: Anirban
authors.initials: A
authors.lastname: Samanta
authors.forename: Jeanette
authors.initials: J
authors.lastname: Nangreave
authors.forename: Hao
authors.initials: H
authors.lastname: Yan
authors.forename: Yan
authors.initials: Y
authors.lastname: Liu
mesh_terms: D019187:Cadmium Compounds / Q000737:chemistry; D004247:DNA / Q000138:chemical synthesis* / Q000737:chemistry* / Q000302:isolation & purification; D005453:Fluorescence; D006046:Gold / Q000737:chemistry; D007259:Infrared Rays; D053768:Metal Nanoparticles / Q000737:chemistry; D045663:Quantum Dots; D012666:Semiconductors; D013440:Sulfides / Q000737:chemistry; D013691:Tellurium / Q000737:chemistry; D014466:Ultraviolet Rays
chemical_list: D019187:Cadmium Compounds; D013440:Sulfides; C034939:cadmium sulfide; D006046:Gold; D004247:DNA; D013691:Tellurium; C028337:cadmium telluride