title: Fast and sensitive DNA hybridization assays using microwave-accelerated metal-enhanced fluorescence.
abstract: A new, fast, and sensitive DNA hybridization assay platform based on microwave-accelerated metal-enhanced fluorescence (MAMEF) is presented. Thiolated oligonucleotide anchors were immobilized onto silver nanoparticles on a glass substrate. The hybridization of the complementary fluorescein-labeled DNA target with the surface-bound oligonucleotides was completed within 20 s upon heating with low-power microwaves. In addition, the signal is optically amplified, a consequence of close proximity of the fluorophore to the silvered substrate. In this proof-of-principle methodology, as low as 50 nM of a target DNA was detected, although we envisage far-lower detection limits. Control experiments, where the surface-bound oligonucleotide was omitted, were also performed to determine the extent of non-specific binding. In these studies a significantly reduced non-specific adsorption was found when using microwave heating near to silvered structures as compared to room temperature incubation. These findings suggest that MAMEF could be a most useful alternative to the DNA hybridization assays used today, especially with regard to substantially increasing both the assay rapidity and sensitivity.
authors.affiliation: Institute of Fluorescence, Laboratory for Advanced Medical Plasmonics, Medical Biotechnology Center, University of Maryland Biotechnology Institute, 725 West Lombard St, Baltimore, MD 21201, USA.
authors.forename: Kadir
authors.initials: K
authors.lastname: Aslan
authors.forename: Stuart N
authors.initials: SN
authors.lastname: Malyn
authors.forename: Chris D
authors.initials: CD
authors.lastname: Geddes
mesh_terms: D000609:Aminoacridines; D004247:DNA / Q000032:analysis* / Q000528:radiation effects; D008872:Microwaves; D049329:Nanostructures; D009693:Nucleic Acid Hybridization / Q000379:methods*; D012834:Silver / Q000737:chemistry; D013050:Spectrometry, Fluorescence / Q000379:methods*
chemical_list: D000609:Aminoacridines; D012834:Silver; D004247:DNA; C025902:acridine yellow