title: Binding assay for cholera toxin based on sequestration electrochemistry using lactose labeled with an electroactive compound.
abstract: A simple electrochemical binding assay for cholera toxin (CT) was developed using lactose labeled with daunomycin as an electroactive compound. The labeled lactose (LL) was determined with high sensitivity by adsorptive stripping voltammetry (AdSV). The electrochemical behaviors of LL at glassy carbon (GC), plastic formed carbon (PFC) and carbon nanotubes paste (CNTP) electrode were investigated. The CNTP electrode showed the greatest accumulation capacity for LL. The assay for CT based on the sequestration electrochemistry was demonstrated. The binding event of the LL to CT was detected by the decrease in the electrochemical response of daunomycin as an electroactive label without a separation process to remove the free LL from the one bound with CT before any measurements can be made. The detection limit of the CT assay using the CNTP electrode was 0.5 nM (42 ng mL(-1)).
authors.affiliation: Department of Environmental Biology and Chemistry, Graduate School of Science and Engineering for Research, University of Toyama, Gofuku 3190, Toyama, 930-8555, Japan. kuramitz@sci.u-toyama.ac.jp
authors.forename: Hideki
authors.initials: H
authors.lastname: Kuramitz
authors.forename: Shun
authors.initials: S
authors.lastname: Miyagaki
authors.forename: Eiji
authors.initials: E
authors.lastname: Ueno
authors.forename: Noriko
authors.initials: N
authors.lastname: Hata
authors.forename: Shigeru
authors.initials: S
authors.lastname: Taguchi
authors.forename: Kazuharu
authors.initials: K
authors.lastname: Sugawara
mesh_terms: D002244:Carbon / Q000737:chemistry; D002772:Cholera Toxin / Q000737:chemistry* / Q000378:metabolism; D003630:Daunorubicin / Q000737:chemistry; D055664:Electrochemical Techniques / Q000379:methods*; D004566:Electrodes; D007785:Lactose / Q000737:chemistry*; D037742:Nanotubes, Carbon / Q000737:chemistry; D010084:Oxidation-Reduction; D011485:Protein Binding
chemical_list: D037742:Nanotubes, Carbon; D002244:Carbon; D002772:Cholera Toxin; D007785:Lactose; D003630:Daunorubicin