title: Amplified fluorescent sensing of DNA using graphene oxide and a conjugated cationic polymer.
abstract: We explore the interactions between a fluorescein (FAM)-labeled single-stranded DNA (P), graphene oxide (GO), and a cationic conjugated polymer, poly [(9,9-bis(6'-N,N,N-trimethylammonium)hexyl)-fluorenylene phenylene dibromide] (PFP). It is found that the fluorescence change of P-GO-PFP system is dependent on the addition order of P and PFP. When adding PFP into P/GO complex, the fluorescence resonance energy transfer (FRET) from PFP to P is inefficient. If P is added to PFP/GO complex, efficient FRET is obtained. This may be attributed to the equal binding ability for P and PFP to GO. The results of time-resolved fluorescence and fluorescence anisotropy support the different fluorescent response under different addition order of P and PFP to GO. Based on the above phenomenon, we demonstrate a method to reduce the high background signal of a traditional PFP-based DNA sensor by introducing GO. In comparison to the use of single PFP, the combination of PFP with GO-based method shows enhanced sensitivity with a detection limit as low as 40 pM for target DNA detection.
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Research Center for Nanobiology and Nanomedicine (MOE 985 Innovative Platform), Wuhan Institute of Biotechnology, and State Key Laboratory of Virology, Wuhan University, Wuhan 430072, China.
authors.forename: Xiao-Jing
authors.initials: XJ
authors.lastname: Xing
authors.forename: Xue-Guo
authors.initials: XG
authors.lastname: Liu
authors.forename: Yue
authors.initials: Y
authors.lastname: He
authors.forename: Yi
authors.initials: Y
authors.lastname: Lin
authors.forename: Cui-Ling
authors.initials: CL
authors.lastname: Zhang
authors.forename: Hong-Wu
authors.initials: HW
authors.lastname: Tang
authors.forename: Dai-Wen
authors.initials: DW
authors.lastname: Pang
mesh_terms: D002412:Cations; D004277:DNA, Single-Stranded / Q000032:analysis* / Q000737:chemistry; D019793:Fluorescein / Q000032:analysis / Q000737:chemistry; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods*; D006108:Graphite / Q000032:analysis* / Q000737:chemistry; D010087:Oxides / Q000032:analysis* / Q000737:chemistry; D011108:Polymers / Q000032:analysis* / Q000737:chemistry
chemical_list: D002412:Cations; D004277:DNA, Single-Stranded; D010087:Oxides; D011108:Polymers; D006108:Graphite; D019793:Fluorescein