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

SIRLEY V. PEREIRA; FRANCO A. BERTOLINO; MARTÍN A. FERNÁNDEZ-BALDO; GERMÁN A. MESSINA; ELOY SALINAS; MARÍA I. SANZ; JULIO RABA

ANALYST

ROYAL SOC CHEMISTRY

Año: 2011 vol. 136 p. 4745 - 4751

0003-2654

In this article we report the development of an integrated microfluidic system coupled to a screenprintedcarbon electrode (SPCE) applied to the quantitative determination of IgG specific antibodiespresent in serum samples of patients that suffer from Chagas disease. This relevant parasitic infectioncaused by the hemoflagellate protozoan Trypanosoma cruzi represents a major public health concern inLatin 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 developedmicrofluidic immunosensor with immobilized T. cruzi proteins on the SPCE surface was successfullyapplied in the detection of specific IgG anti-T. cruzi antibodies, which were allowed to reactimmunologically with immobilized T. cruzi antigen. After that, labelled antibodies were quantifiedthrough 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 ofhydrogen peroxide (H2O2) catalyzes the oxidation of 4-TBC whose back electrochemical reduction wasdetected on a modified electrode at 100 mV. The calculated detection limit for electrochemicaldetection was 3.065 ng mL1 and the intra- and inter-assay coefficients of variation were below 6.95%.