title: Electrochemical assay of nonlabeled DNA chip and SNOM imaging by using streptavidin-biotin interaction.
abstract: The assay of DNA biosensor-based nucleic acid recognition using microfabrication technology provides for high sensitivity, good surface coverage and reproducibility. We have achieved efficient immobilization and hybridization of nonlabeled DNA using cyclic voltammetry (CV), square wave voltammetry (SWV) and scanning near-field optical microscopy (SNOM) techniques. The increased electrochemical response observed following the immobilization of biotinlyated ssDNA probe suggests that nucleic acid is a somewhat better medium for electronic transfer. We demonstrated the high coverage of immobilized FITC-labeled biotinylated DNA probe on a streptavidin-modified surface using SNOM imaging. SNOM imaging of FITC-labeled complementary DNA also exhibited fluorescent light spots of hybridization distributed throughout. No fluorescent light was observed with the hybridization of non-complementary DNA.
authors.affiliation: The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan.
authors.forename: HeaYeon
authors.initials: H
authors.lastname: Lee
authors.forename: JongWan
authors.initials: J
authors.lastname: Park
authors.forename: HoSup
authors.initials: H
authors.lastname: Jung
authors.forename: JongMin
authors.initials: J
authors.lastname: Kim
authors.forename: Tomoji
authors.initials: T
authors.lastname: Kawai
mesh_terms: D001710:Biotin / Q000737:chemistry*; D019921:Biotinylation; D004247:DNA / Q000737:chemistry; D004277:DNA, Single-Stranded / Q000737:chemistry; D004563:Electrochemistry / Q000379:methods*; D007091:Image Processing, Computer-Assisted; D018625:Microscopy, Atomic Force / Q000379:methods*; D008855:Microscopy, Electron, Scanning; D036103:Nanotechnology / Q000379:methods*; D009693:Nucleic Acid Hybridization; D020411:Oligonucleotide Array Sequence Analysis; D019809:Streptavidin / Q000737:chemistry*
chemical_list: D004277:DNA, Single-Stranded; D001710:Biotin; D004247:DNA; D019809:Streptavidin