title: Amplification of fluorescence detection of DNA based on magnetic separation.
abstract: A novel nanoparticles-based fluorescence detection method has been developed by taking advantage of magnetic separation and amplified fluorescence detection. This DNA sensor relies on a "sandwich" hybridization strategy, in which the DNA targets are first hybridized to captured oligonucleotide probes immobilized on magnetic nanoparticles, and then hybridized with thiol-modified oligonucleotide probes immobilized on gold nanoparticles. Subsequently, the amplified DNA signals are detected in the form of bio-bar-code DNA using a chip-based fluorescence detection method. The result showed that the detection limit of target DNA probes is 1 pM. Complementary and mismatched sequences were clearly distinguished, and the ratio of the background-subtracted fluorescence values for complementary and single-base mismatched oligonucleotide was 2.12:1. This new system can be applied to both DNA detection and immunoassay, and has broad potential applications in disease diagnosis and immunoassay.
authors.affiliation: Key Laboratory of Green Packaging and Application of Biological Nanotechnology, Hunan University of Technology, Zhuzhou 412008, P.R. China. libonie@yahoo.com.cn
authors.forename: Li-bo
authors.initials: LB
authors.lastname: Nie
authors.forename: Xiu-li
authors.initials: XL
authors.lastname: Wang
authors.forename: Song
authors.initials: S
authors.lastname: Li
authors.forename: Hong
authors.initials: H
authors.lastname: Chen
mesh_terms: D001483:Base Sequence; D004247:DNA / Q000032:analysis* / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*; D001330:Electronic Data Processing; D052203:Ferrosoferric Oxide / Q000737:chemistry; D006046:Gold / Q000737:chemistry; D008280:Magnetics; D053768:Metal Nanoparticles / Q000737:chemistry; D009693:Nucleic Acid Hybridization; D013050:Spectrometry, Fluorescence; D013438:Sulfhydryl Compounds / Q000737:chemistry; D013499:Surface Properties
chemical_list: D013438:Sulfhydryl Compounds; D006046:Gold; D004247:DNA; D052203:Ferrosoferric Oxide