title: DNA electrochemical sensor using osmium complex.
abstract: The [Os(DA-bpy)2DPPZ]2+ complex (DPPZ; dipyrido [a:2',3'-c] phenazine, DA-bpy; 4,4'-diamino-2,2'-bipyridine) had a lower half-wave potential (E1/2) of 147 mV (vs. Ag|AgCl) and higher binding affinity with DNA (binding constant, K = 3.1 x 10(7) M-1) than those of DPPZ type metal complexes. With a single stranded DNA (ssDNA) immobilized gold electrode, the hybridization signal (delta I) of the [Os(DA-bpy)2DPPZ]2+ complex was linear in the concentration range of 1.0 pg ml-1-0.12 microgram ml-1 for the targeted DNA with a regression coefficient of 0.999. The detection limit was 0.1 pg ml-1. The 400 bp yAL3 gene was also detected with good sensitivity and selectivity using the [Os(DA-bpy)2DPPZ]2+ complex.
authors.affiliation: Department of Chemical Science and Technology, Faculty of Engineering, University of Tokushima, Minami-josanjima 2-1, Tokushima 770-8506, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Maruyama
authors.forename: Y
authors.initials: Y
authors.lastname: Mishima
authors.forename: J
authors.initials: J
authors.lastname: Motonaka
mesh_terms: D015374:Biosensing Techniques; D004247:DNA / Q000032:analysis* / Q000378:metabolism; D004563:Electrochemistry; D004566:Electrodes; D005796:Genes; D046911:Macromolecular Substances; D015335:Molecular Probes / Q000737:chemistry*; D009693:Nucleic Acid Hybridization / Q000379:methods*; D009942:Organometallic Compounds / Q000737:chemistry* / Q000378:metabolism; D013997:Time Factors
chemical_list: C476357:(4,4'-diamino-2,2'-bipyridine)(dipyrido(a-2',3'-c)phenazine)osmium(II); D046911:Macromolecular Substances; D015335:Molecular Probes; D009942:Organometallic Compounds; D004247:DNA