Artículos de revistas
Investigation of the interaction between Tc85-11 protein and antibody anti-T cruzi by AFM and amperometric measurements
Date
2006-07-15Registration in:
Electrochimica Acta. Oxford: Pergamon-Elsevier B.V., v. 51, n. 24, p. 5046-5052, 2006.
0013-4686
10.1016/j.electacta.2006.03.061
WOS:000239253900005
1923726000036625
6720223715917381
0000-0002-3350-8308
Author
Universidade Estadual Paulista (Unesp)
Universidade de São Paulo (USP)
Univ Barcelona
Institutions
Abstract
This 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.