title: Decorated graphene sheets for label-free DNA impedance biosensing.
abstract: An efficient DNA impedance biosensing platform is constructed, in which positively charged N,N-bis-(1-aminopropyl-3-propylimidazol salt)-3,4,9,10-perylene tetracarboxylic acid diimide (PDI) is anchored to graphene sheets. The π-π stacking and electronic interactions are elucidated by the distinct absorption features in UV-vis spectra and by quenching perylene fluorescence in contact with graphene. The rational design and tailoring of graphene surface invest it with desired properties (dispersive, structural, photoelectrical and conductive, etc.) and boost its application. Electrostatic interaction between PDI's positively charged imidazole rings and negatively charged phosphate backbones of single-stranded DNA (ssDNA) facilitates ssDNA immobilization. This manner is different from these mainly based on the attraction between the rings in DNA bases and the hexagonal cells of graphene, which is disturbed after hybridization and causes the leaving of formed double-stranded DNA from graphene surface. The electrostatic ssDNA grafting occupies phosphate backbones and particularly leaves the bases available for efficient hybridization. DNA immobilization and hybridization lead to PDI/graphene interfacial property changes, which are monitored by electrochemical impedance spectroscopy and adopted as the analytical signal. The conserved sequence of the pol gene of human immunodeficiency virus 1 is satisfactorily detected via this PDI/graphene platform and shows high reproducibility, selectivity.
authors: Engineering Laboratory for Modern Analytical Techniques, c/o State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, PR China.
authors: Yuwei
authors: Y
authors: Hu
authors: Kaikai
authors: K
authors: Wang
authors: Qixian
authors: Q
authors: Zhang
authors: Fenghua
authors: F
authors: Li
authors: Tongshun
authors: T
authors: Wu
authors: Li
authors: L
authors: Niu
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D004247:DNA / Q000032:analysis* / Q000737:chemistry; D004277:DNA, Single-Stranded / Q000032:analysis / Q000737:chemistry; D017097:Electric Impedance; D006108:Graphite / Q000737:chemistry*; D009693:Nucleic Acid Hybridization / Q000379:methods; D010569:Perylene / Q000031:analogs & derivatives* / Q000737:chemistry; D015203:Reproducibility of Results
chemical_list: C560550:3,4,9,10-perylene tetracarboxylic acid; D004277:DNA, Single-Stranded; D010569:Perylene; D006108:Graphite; D004247:DNA