title: A paper-based resonance energy transfer nucleic acid hybridization assay using upconversion nanoparticles as donors and quantum dots as acceptors.
abstract: Monodisperse aqueous upconverting nanoparticles (UCNPs) were covalently immobilized on aldehyde modified cellulose paper via reduction amination to develop a luminescence resonance energy transfer (LRET)-based nucleic acid hybridization assay. This first account of covalent immobilization of UCNPs on paper for a bioassay reports an optically responsive method that is sensitive, reproducible and robust. The immobilized UCNPs were decorated with oligonucleotide probes to capture HPRT1 housekeeping gene fragments, which in turn brought reporter conjugated quantum dots (QDs) in close proximity to the UCNPs for LRET. This sandwich assay could detect unlabeled oligonucleotide target, and had a limit of detection of 13 fmol and a dynamic range spanning nearly 3 orders of magnitude. The use of QDs, which are excellent LRET acceptors, demonstrated improved sensitivity, limit of detection, dynamic range and selectivity compared to similar assays that have used molecular fluorophores as acceptors. The selectivity of the assay was attributed to the decoration of the QDs with polyethylene glycol to eliminate non-specific adsorption. The kinetics of hybridization were determined to be diffusion limited and full signal development occurred within 3 min.
authors.affiliation: Chemical Sensors Group, Department of Chemical and Physical Sciences, University of Toronto Mississauga, 3359 Mississauga Road, Mississauga, ON L5L 1C6, Canada.
authors.forename: Samer
authors.initials: S
authors.lastname: Doughan
authors.affiliation: Chemical Sensors Group, Department of Chemical and Physical Sciences, University of Toronto Mississauga, 3359 Mississauga Road, Mississauga, ON L5L 1C6, Canada.
authors.forename: Uvaraj
authors.initials: U
authors.lastname: Uddayasankar
authors.affiliation: Chemical Sensors Group, Department of Chemical and Physical Sciences, University of Toronto Mississauga, 3359 Mississauga Road, Mississauga, ON L5L 1C6, Canada. Electronic address: ulrich.krull@utoronto.ca.
authors.forename: Ulrich J
authors.initials: UJ
authors.lastname: Krull
mesh_terms: D000818:Animals; D001483:Base Sequence; D004247:DNA / Q000032:analysis* / Q000235:genetics; D005459:Fluorides / Q000737:chemistry; D020043:Genes, Essential; D006801:Humans; D007041:Hypoxanthine Phosphoribosyltransferase / Q000235:genetics; D049408:Luminescent Agents / Q000737:chemistry*; D008163:Luminescent Measurements; D053758:Nanoparticles / Q000737:chemistry*; D009693:Nucleic Acid Hybridization / Q000379:methods*; D015345:Oligonucleotide Probes / Q000737:chemistry / Q000235:genetics; D010209:Paper; D045663:Quantum Dots / Q000737:chemistry*; D015018:Ytterbium / Q000737:chemistry; D015019:Yttrium / Q000737:chemistry
chemical_list: D049408:Luminescent Agents; D015345:Oligonucleotide Probes; C525362:sodium yttriumtetrafluoride; D015019:Yttrium; D004247:DNA; D007041:Hypoxanthine Phosphoribosyltransferase; D015018:Ytterbium; D005459:Fluorides
keywords: Bioassay; Luminescence resonance energy transfer; Nucleic acid hybridization; Paper; Quantum dots; Upconversion nanoparticles