title: Metal-enhanced fluorescence of nano-core-shell structure used for sensitive detection of prion protein with a dual-aptamer strategy.
abstract: Metal-enhanced fluorescence (MEF) as a newly recognized technology is widespread throughout biological research. The use of fluorophore-metal interactions is recognized to be able to alleviate some of fluorophore photophysical constraints, favorably increase both the fluorophore emission intensity and photostability. In this contribution, we developed a novel metal-enhanced fluorescence (MEF) and dual-aptamer-based strategy to achieve the prion detection in solution and intracellular protein imaging simultaneously, which shows high promise for nanostructure-based biosensing. In the presence of prion protein, core-shell Ag@SiO2, which are functionalized covalently by single stranded aptamer (Apt1) of prions and Cyanine 3 (Cy3) decorated the other aptamer (Apt2) were coupled together by the specific interaction between prions and the anti-prion aptamers in solution. By adjusting shell thickness of the pariticles, a dual-aptamer strategy combined MEF can be realized by the excitation and/or emission rates of Cy3. It was found that the enhanced fluorescence intensities followed a linear relationship in the range of 0.05-0.30 nM, which is successfully applied to the detection of PrP in mice brain homogenates.
authors.affiliation: Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, PR China.
authors.forename: Ping Ping
authors.initials: PP
authors.lastname: Hu
authors.forename: Lin Ling
authors.initials: LL
authors.lastname: Zheng
authors.forename: Lei
authors.initials: L
authors.lastname: Zhan
authors.forename: Jing Yun
authors.initials: JY
authors.lastname: Li
authors.forename: Shu Jun
authors.initials: SJ
authors.lastname: Zhen
authors.forename: Hui
authors.initials: H
authors.lastname: Liu
authors.forename: Ling Fei
authors.initials: LF
authors.lastname: Luo
authors.forename: Geng Fu
authors.initials: GF
authors.lastname: Xiao
authors.forename: Cheng Zhi
authors.initials: CZ
authors.lastname: Huang
mesh_terms: D000818:Animals; D052157:Aptamers, Nucleotide / Q000737:chemistry*; D002478:Cells, Cultured; D005456:Fluorescent Dyes / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D006801:Humans; D008670:Metals / Q000737:chemistry; D051379:Mice; D049329:Nanostructures / Q000737:chemistry*; D011328:Prions / Q000032:analysis*; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D052157:Aptamers, Nucleotide; D005456:Fluorescent Dyes; D008670:Metals; D011328:Prions; D006046:Gold; D012822:Silicon Dioxide
keywords: Ag@Si nanoparticles; Aptamer; Metal-enhanced fluorescence; Prion protein