title: A highly selective sandwich-type FRET assay for ATP detection based on silica coated photon upconverting nanoparticles and split aptamer.
abstract: In this paper, we report a highly selective sandwich-type fluorescence resonance energy transfer (FRET) assay for ATP detection by combining the unique optical properties of silica coated photon upconverting NaYF4:Yb(3+), Er(3+) nanoparticles (Si@UCNPs) with the high specific recognition ability of ATP aptamer. In the protocol, a single aptamer of ATP was split into two fragments. One of which was covalently attached to the Si@UCNPs at the 5' end, and the other was labeled with Black Hole Quencher-1 (BHQ1) at the 3' end. In the presence of ATP, the two fragments bound ATP with high affinity to form the sandwich complexes on the surface of Si@UCNPs. ATP induced association of the two fragments, thus bringing the Si@UCNPs and BHQ1 into close proximity. Under the illumination of 980 nm laser, energy transfer took place between the Si@UCNPs as the donor and BHQ1 as the acceptor, creating an optical "sandwich-type" assay for ATP detection. By monitoring the fluorescence change of the Si@UCNPs at 550 nm, the presence of the ATP could be quantitatively detected with a detection limit of 1.70 μM. The linear response range was 2 μM-16 μM. The background of this assay was ignorable because the fluorescence intensity of Si@UCNPs at 550 nm was not changed in the absence of ATP. This assay was also able to discriminate ATP from its analogs.
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of biology, College of Chemistry & Chemical Engineering, Hunan University, Changsha 410082, PR China.
authors.forename: Xiaoxiao
authors.initials: X
authors.lastname: He
authors.forename: Zhangxiu
authors.initials: Z
authors.lastname: Li
authors.forename: Xuekun
authors.initials: X
authors.lastname: Jia
authors.forename: Kemin
authors.initials: K
authors.lastname: Wang
authors.forename: Jinjin
authors.initials: J
authors.lastname: Yin
mesh_terms: D000255:Adenosine Triphosphate / Q000032:analysis* / Q000737:chemistry; D052157:Aptamers, Nucleotide / Q000737:chemistry*; D004871:Erbium / Q000737:chemistry; D005240:Feasibility Studies; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods*; D005459:Fluorides / Q000737:chemistry; D008274:Magnesium / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D019301:Oleic Acid / Q000737:chemistry; D015203:Reproducibility of Results; D012822:Silicon Dioxide / Q000737:chemistry*; D015018:Ytterbium / Q000737:chemistry; D015019:Yttrium / Q000737:chemistry
chemical_list: D052157:Aptamers, Nucleotide; C525362:sodium yttriumtetrafluoride; D019301:Oleic Acid; D015019:Yttrium; D012822:Silicon Dioxide; D004871:Erbium; D000255:Adenosine Triphosphate; D008274:Magnesium; D015018:Ytterbium; D005459:Fluorides