title: Simultaneously amplified electrochemical and surface plasmon optical detection of DNA hybridization based on ferrocene-streptavidin conjugates.
abstract: A sensitive method based on ferrocene-streptavidin (Fc-Stv) conjugates for the simultaneously amplified electrochemical and surface plasmon optical detection of DNA target hybridization to peptide nucleic acid-modified gold surfaces is reported. The attachment of Fc-Stv to the biotinylated complementary target DNA not only amplified the surface plasmon resonance signal but also enhanced the electrochemical signal due to the many Fc markers per Stv. The ferrocene redox peak current increased with the increase of the target DNA concentration. Consequently, the amount of hybridized target DNA can be estimated by cyclic voltammetry and chronocoulometry. The detection limit of this DNA sensor is 10 pM (2 fmol, with signal to noise > 3). This sensor was also shown to have high selectivity (at the single-base mismatch level) and good reproducibility.
authors.affiliation: Max-Planck-Institute for Polymer Research, Ackermannweg 10, D-55128, Mainz, Germany.
authors.forename: Jianyun
authors.initials: J
authors.lastname: Liu
authors.forename: Shengjun
authors.initials: S
authors.lastname: Tian
authors.forename: Louis
authors.initials: L
authors.lastname: Tiefenauer
authors.forename: Peter Eigil
authors.initials: PE
authors.lastname: Nielsen
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Knoll
mesh_terms: D004247:DNA / Q000737:chemistry*; D004563:Electrochemistry / Q000379:methods*; D005296:Ferrous Compounds / Q000737:chemistry*; D000075163:Metallocenes; D009693:Nucleic Acid Hybridization; D020135:Peptide Nucleic Acids / Q000737:chemistry*; D019809:Streptavidin / Q000737:chemistry*; D020349:Surface Plasmon Resonance / Q000379:methods*
chemical_list: D005296:Ferrous Compounds; D000075163:Metallocenes; D020135:Peptide Nucleic Acids; D004247:DNA; D019809:Streptavidin; C004998:ferrocene