title: Assessment of the interaction between a synthetic epitope of troponin C and its specific antibody using a label-free faradaic impedimetric immunosensor and alpha-Keggin silicotungstic heteropolyacid as a redox probe.
abstract: The development of an immunosensor for the direct probing of the interaction between a cysteine-modified synthetic peptide, which corresponds to the epitope cTnC-89-98 of troponin C, and its specific antibody is described. Following immobilization of the peptide onto gold electrodes through the formation of a self-assembled monolayer, the alteration of the interfacial properties of the electrodes upon peptide-antibody interaction was traced by faradaic electrochemical impedance spectroscopy (EIS) using a silicotungstic heteropolyacid, H(4)SiO(4).12WO(3), as a redox probe. The electrochemical behaviour of the redox probe was evaluated with cyclic voltammetry and EIS. The effect of milk protein or 4-mercaptophenol, which was used as post-blocking agents, on the performance of the immunosensor, was investigated. Treatment with 4-mercaptophenol resulted in immunoeffective electrodes that successfully tested in anti-serum samples. An optimum dilution ratio of the samples, where the effect of the matrix on the measuring signal is negligible, was also determined.
authors.affiliation: Department of Chemistry, University of Ioannina, 45110 Ioannina, Greece.
authors.forename: Aikaterini G
authors.initials: AG
authors.lastname: Mantzila
authors.forename: Constantinos
authors.initials: C
authors.lastname: Strongylis
authors.forename: Vassilios
authors.initials: V
authors.lastname: Tsikaris
authors.forename: Mamas I
authors.initials: MI
authors.lastname: Prodromidis
mesh_terms: D000937:Antigen-Antibody Reactions; D015374:Biosensing Techniques / Q000379:methods*; D017097:Electric Impedance; D004563:Electrochemistry; D004566:Electrodes; D000939:Epitopes; D007118:Immunoassay / Q000379:methods*; D010084:Oxidation-Reduction; D017640:Silicates / Q000737:chemistry; D013057:Spectrum Analysis; D019209:Troponin C / Q000032:analysis* / Q000276:immunology; D017973:Tungsten Compounds / Q000737:chemistry
chemical_list: D000939:Epitopes; D017640:Silicates; D019209:Troponin C; D017973:Tungsten Compounds; C021746:silicotungstic acid