title: Sensitive spectrofluorometry of cellular prion protein based on the on-off interaction between fluorescent dye-labelled aptamers and multi-walled carbon nanotubes.
abstract: The very simple and general spectrofluorometry of cellular prion protein (PrP(C)) is reported in this contribution based on the on-off noncovalent interaction of fluorescent dye-labelled PrP(C) DNA aptamers with multi-walled carbon nanotubes (MWCNTs). Due to the π-π stacking interaction between the DNA bases of the aptamer and the carbon nanotubes, the fluorescent dye and the MWCNTs are brought into close proximity, which leads to fluorescence quenching with a ratio of up to 87%. However, further addition of PrP(C), which disturbs the π-π interaction owing to the strong and specific binding of the aptamer to PrP(C), driving the aptamer away from the surface of the MWCNTs, restored the quenched fluorescence. This recovered fluorescence intensity was found to be in linear proportion to the PrP(C) concentration in the range of 8.2 to 81.7 nM, which builds the basis of the spectrofluorometry of the cellular prion protein.
authors.affiliation: Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhan
authors.forename: Li
authors.initials: L
authors.lastname: Peng
authors.forename: Yan
authors.initials: Y
authors.lastname: Yu
authors.forename: Shu Jun
authors.initials: SJ
authors.lastname: Zhen
authors.forename: Cheng Zhi
authors.initials: CZ
authors.lastname: Huang
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000633:toxicity; D001483:Base Sequence; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D005456:Fluorescent Dyes / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D037742:Nanotubes, Carbon / Q000737:chemistry*; D011328:Prions / Q000737:chemistry* / Q000378:metabolism*; D012235:Rhodamines / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013379:Substrate Specificity
chemical_list: C114557:5-carboxytetramethylrhodamine succinimidyl ester; D052157:Aptamers, Nucleotide; D005456:Fluorescent Dyes; D037742:Nanotubes, Carbon; D011328:Prions; D012235:Rhodamines