microfluidic device based on a screen-printed carbon electrode with electrodeposited gold nanoparticles for the detection of IgG anti-Trypanosoma cruzi antibodies

PEREIRA SIRLEY V.; FRANCO A. BERTOLINO; FERNANDEZ BALDO M.; GERMÁN A. MESSINA; SALINAS E.; MARIA I. SANZ; JULIO RABA

ANALYST

ROYAL SOC CHEMISTRY

Lugar: Cambridge; Año: 2011 p. 1745 - 1751

0003-2654

Abstract In this article we report the development of an integrated microfluidic system coupled to a screenprinted carbon electrode (SPCE) applied to the quantitative determination of IgG specific antibodiespresent in serum samples of patients that suffer from Chagas disease. This relevant parasitic infection caused by the hemoflagellate protozoan Trypanosoma cruzi represents a major public health concern in Latin America. In order to perform the detection of mentioned antibodies, SPCE coupled toa microfluidic device was modified by electrodeposition of gold nanoparticles (AuNPs) andfunctionalized with Trypanosoma cruzi proteins from epimastigote membranes. The developed microfluidic immunosensor with immobilized T. cruzi proteins on the SPCE surface was successfully applied in the detection of specific IgG anti-T. cruzi antibodies, which were allowed to react immunologically with immobilized T. cruzi antigen. After that, labelled antibodies were quantified through the addition of horseradish peroxidase (HRP) enzyme-labeled secondary antibodies specific tohuman IgG, using 4-tert-butylcatechol (4-TBC) as enzymatic mediator. HRP in the presence of hydrogen peroxide (H2O2) catalyzes the oxidation of 4-TBC whose back electrochemical reduction was detected on a modified electrode at _100 mV. The calculated detection limit for electrochemical detection was 3.065 ng mL_1 and the intra- and inter-assay coefficients of variation were below 6.95%.