Ferreira, A. A. P.Colli, W.Alves, M. J. M.Oliveira, D. R.Costa, P. I.Guell, A. G.Sanz, F.Benedetti, Assis Vicente [UNESP]Yamanaka, Hideko [UNESP]2014-05-202014-05-202006-07-15Electrochimica Acta. Oxford: Pergamon-Elsevier B.V., v. 51, n. 24, p. 5046-5052, 2006.0013-4686http://hdl.handle.net/11449/7533This present work reports on development of an amperometric immunosensor for the diagnosis of Chagas' disease using a specific glycoprotein of the trypomastigote surface, which belongs to the Tc85-11 protein family of Trypanosoma cruzi (T cruzi). An atomically flat gold surface on a silicon substrate and gold screen-printed electrodes were functionalized with cystatrine and later activated with glutaraldehyde (GA), which was used to form covalent bonds with the purified recombinant antigen (Tc85-11). The antigen reacts with the antibody from the serum, and the affinity reaction was monitored directly using atomic force microscopy or amperometry through a secondary antibody tagged to peroxidase (HRP). Surface imaging allowed to us to differentiate the modification steps and antigen-antibody interaction allowed to distinguish the affinity reactions. In the amperometric immunosensor, peroxidase catalyses the L-2 formation in the presence of hydrogen peroxide and potassium iodide, and the reduction current intensity was measured at a given potential with screen-printed electrodes. The immunosensor was applied to sera of chagasic patients and patients having different systemic diseases. (c) 2006 Elsevier Ltd. All rights reserved.5046-5052engChagas' diseaseTc85-11 proteinamperometric immunosensorAFMArtigo10.1016/j.electacta.2006.03.061WOS:000239253900005Acesso restrito192372600003662567202237159173810000-0002-3350-8308