title: Graphene oxide-hairpin probe nanocomposite as a homogeneous assay platform for DNA base excision repair screening.
abstract: Uracil-DNA glycosylase (UDG) as one of the most important base excision repair enzymes plays a crucial role in protecting the genome from endogenous DNA damage and sustaining the genome integrity. Quantitative activity analysis of UDG is a central challenge and of fundamental importance in bioanalysis. Here, we proposed a novel biosensor constituted by adsorbing a fluorophore-labeled hairpin probe onto the surface of graphene oxide (GO) as a homogeneous assay platform for sensitive UDG activity assay. Active UDG could excise the uracil base in the hairpin probe, and further hydrolysis of the leaving abasic site gave rise to high fluorescence. Thus, it provided a convenient approach for UDG activity quantification. Because of the unique ability of GO in universal fluorescence quenching, a low background fluorescence signal can be obtained for the efficient fluorescence resonant energy transfer from the fluorophore-labeled on the hairpin probe to GO sheet. A quite wide dynamic range from 0.0017 U/mL to 0.8 U/mL was achieved for UDG assay and the detection limit was estimated to be 0.0008 U/mL. The results indicated that this strategy offers a simple, cost-effective, highly sensitive and selective homogeneous detection platform for UDG activity assay related biochemical studies.
authors.affiliation: State Key Laboratory for Chemo/biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, PR China.
authors.forename: Dian-Ming
authors.initials: DM
authors.lastname: Zhou
authors.forename: Qiang
authors.initials: Q
authors.lastname: Xi
authors.forename: Man-Fen
authors.initials: MF
authors.lastname: Liang
authors.forename: Cui-Hua
authors.initials: CH
authors.lastname: Chen
authors.forename: Li-Juan
authors.initials: LJ
authors.lastname: Tang
authors.forename: Jian-Hui
authors.initials: JH
authors.lastname: Jiang
mesh_terms: D001483:Base Sequence; D015374:Biosensing Techniques / Q000295:instrumentation*; D004260:DNA Repair / Q000235:genetics*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006108:Graphite / Q000737:chemistry*; D055029:Inverted Repeat Sequences / Q000235:genetics*; D015336:Molecular Probe Techniques / Q000295:instrumentation*; D008969:Molecular Sequence Data; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA / Q000295:instrumentation*
chemical_list: D006108:Graphite