title: Amperometric immunosensor for detecting Schistosoma mansoni antibody.
abstract: An immunosensor for detecting the antibody anti-apyrase of Schistosoma mansoni based on rigid composite materials, containing graphite powder and epoxy resins, developed in this work, is described. A surface modification strategy for the use of oxidized graphite in the detection of antibody-antigen interaction was developed. This modification strategy is based on silanization of conductive composite. First, the graphite powder-epoxy resin was treated with concentrated hydrogen peroxide to improve surface hydroxyl groups and to form a hydrophilic layer. Second, 3- aminopropyltriethoxysilane was subsequently used to functionalize the treated surface to form amino groups, which were further activated with glutaraldehyde to introduce a layer of aldehyde groups. Contact angle microscopy and scanning electron microscopy were used as a qualitative analysis of the deposition of silane on the surface of the sensor. The effectiveness of the modification strategy was validated by amperometric immunoassays of S. mansoni. Amperometric signals related to concentrations of this immobilized protein were observed, and the effects of pH and incubation times were analyzed. This surface modification strategy provides a platform on which proteins can be directly immobilized for immunosensor and protein array applications.
authors.affiliation: Escola de Química, Centro de Tecnologia, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil. ninoska@eq.ufrj.br
authors.forename: Ninoska I
authors.initials: NI
authors.lastname: Bojorge-Ramírez
authors.forename: Andréa Medeiros
authors.initials: AM
authors.lastname: Salgado
authors.forename: Belkis
authors.initials: B
authors.lastname: Valdman
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000032:analysis*; D001081:Apyrase / Q000737:chemistry; D002021:Buffers; D004563:Electrochemistry; D004566:Electrodes; D004797:Enzyme-Linked Immunosorbent Assay; D004800:Enzymes, Immobilized; D004852:Epoxy Compounds; D006108:Graphite; D006358:Hot Temperature; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007120:Immunochemistry / Q000295:instrumentation*; D007202:Indicators and Reagents; D008855:Microscopy, Electron, Scanning; D012550:Schistosoma mansoni / Q000276:immunology*; D012555:Schistosomiasis mansoni / Q000175:diagnosis / Q000276:immunology; D012699:Serology / Q000295:instrumentation; D013696:Temperature
chemical_list: D000913:Antibodies, Protozoan; D002021:Buffers; D004800:Enzymes, Immobilized; D004852:Epoxy Compounds; D007202:Indicators and Reagents; D006108:Graphite; D006861:Hydrogen Peroxide; D001081:Apyrase