title: A Simple Interfacial Platform for Homogeneous Electrochemical Immunoassays Using a Poly(Vinylimidazole)-Modified Electrode.
abstract: In this study, a homogeneous method featuring simple, one-step detection was developed to analyze hippuric acid (HA), a major metabolite of toluene. High sensitivity was achieved with the facile immobilization of poly(vinylimidazole) (PVI) on an indium tin oxide (ITO) electrode. Using a previously developed approach, pentacyanoferrate was coordinated with pyridyl-Nligands, and the redox-active Fe(II/III) centers were bound to Ni(II) ions on the electrode via electrostatic cyanide bridges. The detection was accomplished by the competitive binding of free HA and pentacyanoferrate-(4-aminomethylpyridine-hippuric acid) (Fe-HA, the electron transfer mediator) to the HA antibody on the Ni(II) ions-modified PVI-ITO (Ni-PVI-ITO) electrode. The electrical and physicochemical characterization of the electrode was carried out by cyclic voltammetry, differential pulse voltammetry, field emission scanning electron microscopy, and X-ray photoelectron spectroscopy. At low mediator concentrations, the electrical signals were proportional to the HA concentration between 0.1 µg/mL and 1.0 mg/mL. The same method may be extended to other small organic molecules.
authors.affiliation: Department of Chemistry, College of Natural Science, Dankook University, Anseo-Dong, Cheonan, Chungnam 330-714, Korea. chem0404@dankook.ac.kr.
authors.forename: Young-Bong
authors.initials: YB
authors.lastname: Choi
authors.affiliation: Department of Nanobiomedical Sciences and BK21 PLUS NBM Global Research Center for Regenerative Medicine, Dankook University, Anseo-Dong, Cheonan, Chungnam 330-714, Korea. powerwy@hanmail.net.
authors.forename: Won-Yong
authors.initials: WY
authors.lastname: Jeon
authors.affiliation: Department of Chemistry, College of Natural Science, Dankook University, Anseo-Dong, Cheonan, Chungnam 330-714, Korea. hankim@dankook.ac.kr.
authors.forename: Hyug-Han
authors.initials: HH
authors.lastname: Kim
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D055664:Electrochemical Techniques / Q000379:methods; D004566:Electrodes; D006626:Hippurates / Q000737:chemistry; D007118:Immunoassay / Q000379:methods; D010084:Oxidation-Reduction; D056951:Photoelectron Spectroscopy / Q000379:methods
chemical_list: D006626:Hippurates; C030514:hippuric acid
keywords: electrochemical biosensor; hippuric acid; immunoassay; mediator; nickel ion