An o-aminobenzoic acid film-based immunoelectrode for detection of the cardiac troponin T in human serum

An amperometric immunosensor for cardiac troponin T detection in human serum troponin T, a marker considered as “gold standard” for acute myocardial infarction diagnosis, is described. A stable carboxylic film to covalently bind antibodies against cTnT onto electrode surface was achieved with electropolymerization of the o-aminobenzoic acid. A fractional factorial study was performed to optimize the electropolymerization parameters. Cyclic voltammetry assays were carried out for characterize steps of the modified electrode surface. The obtained calibration curve at −0.05 V by amperometry presented a good linear response range from 0.05 to 5.0 ng mL−1 cTnT with a correlation coefficient of 0.992 (n = 6) and 0.016 ng mL−1 detection limit. The electrodes showed a good stability upon the analytical responses retaining 91.6% of its initial response after 18 days. This sensor showed outgoing results regarding sensitivity allowing reliable measurements of the cTnT at levels of clinical significance for acute myocardial infarctions diagnosis.

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► An immunosensor based on polymer film was developed for cardiac troponin T (cTnT).
► Anti-cTnT was immobilized on o-aminobenzoic acid film.
► A detection limit of 16.0 pg mL−1 troponin T was achieved.
► It was analyzed the troponin T in human serum.