title: An amplified graphene oxide-based fluorescence aptasensor based on target-triggered aptamer hairpin switch and strand-displacement polymerization recycling for bioassays.
abstract: An amplified graphene oxide (GO) based fluorescence aptasensor based on target-triggered aptamer hairpin switch and strand-displacement polymerization recycling is developed for bioassays. The dye-labeled single-strand DNA (aptamer hairpin) was adsorbed on the surface of GO, which result in the fluorescence quenching of dye, and exhibiting minimal background fluorescence. Upon the target, primer and polymerase, the stem of the aptamer hairpin was opened, and binds with the primer to triggers the circular target strand-displacement polymerization reaction, which produces huge amounts of duplex helixes DNA and lead to strong fluorescence emission due to shielding of nucelobases within its double-helix structure. During the polymerization reaction, the primer was extended, and target was displaced. And the displaced target recognizes and hybridizes with another hairpin probe, triggering the next round of polymerization reaction, and the circle process induces fluorescence signal amplification for the detection of analyte. To test the feasibility of the aptasensor systems, interferon-gamma (IFN-γ) was employed as a model analyte. A detection limit as low as 1.5 fM is obtained based on the GO aptasensor with a linear range of three orders of magnitude. The present method was successfully applied for the detection of IFN-γ in human plasma.
authors.affiliation: Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources, Ministry of Education, College of Chemistry and Chemical Engineering, Guangxi Normal University, Guilin 541004, PR China. hukun216@163.com
authors.forename: Kun
authors.initials: K
authors.lastname: Hu
authors.forename: Jinwen
authors.initials: J
authors.lastname: Liu
authors.forename: Jia
authors.initials: J
authors.lastname: Chen
authors.forename: Yong
authors.initials: Y
authors.lastname: Huang
authors.forename: Shulin
authors.initials: S
authors.lastname: Zhao
authors.forename: Jianniao
authors.initials: J
authors.lastname: Tian
authors.forename: Guohai
authors.initials: G
authors.lastname: Zhang
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry; D015374:Biosensing Techniques / Q000379:methods*; D004277:DNA, Single-Stranded / Q000737:chemistry*; D005453:Fluorescence; D006108:Graphite / Q000737:chemistry*; D006801:Humans; D007371:Interferon-gamma / Q000097:blood / Q000302:isolation & purification*; D009693:Nucleic Acid Hybridization; D010087:Oxides / Q000737:chemistry*; D058105:Polymerization; D013050:Spectrometry, Fluorescence
chemical_list: D052157:Aptamers, Nucleotide; D004277:DNA, Single-Stranded; D010087:Oxides; D006108:Graphite; D007371:Interferon-gamma