A Polypyrrole/Nanoclay Hybrid Film for Ultra-Sensitive Cardiac Troponin T Electrochemical Immunosensor
Vicente P. A. Landim,
Marcos V. Foguel,
Cecília M. Prado,
Maria P. T. Sotomayor,
Iolanda C. Vieira,
Bárbara V. M. Silva,
Rosa F. Dutra
Affiliations
Vicente P. A. Landim
Biomedical Engineering Laboratory, Department of Biomedical Engineering, Federal University of Pernambuco, Av. Prof. Moraes Rego, 1235, Recife 50670-901, Brazil
Marcos V. Foguel
Biomedical Engineering Laboratory, Department of Biomedical Engineering, Federal University of Pernambuco, Av. Prof. Moraes Rego, 1235, Recife 50670-901, Brazil
Cecília M. Prado
Biomedical Engineering Laboratory, Department of Biomedical Engineering, Federal University of Pernambuco, Av. Prof. Moraes Rego, 1235, Recife 50670-901, Brazil
Maria P. T. Sotomayor
Institute of Chemistry, State University of São Paulo (UNESP), Araraquara 14801-970, Brazil
Iolanda C. Vieira
Laboratory of Biosensors, Department of Chemistry, Federal University of Santa Catarina (UFSC), Florianopolis 88040-900, Brazil
Bárbara V. M. Silva
Biomedical Engineering Laboratory, Department of Biomedical Engineering, Federal University of Pernambuco, Av. Prof. Moraes Rego, 1235, Recife 50670-901, Brazil
Rosa F. Dutra
Biomedical Engineering Laboratory, Department of Biomedical Engineering, Federal University of Pernambuco, Av. Prof. Moraes Rego, 1235, Recife 50670-901, Brazil
An electrochemical immunosensor based on a nanohybrid film of carboxylated polypyrrole and amine nanoclay was developed for label-free detection of the human cardiac troponin T (cTnT). The nanohybrid film was formed in situ on the surface of the glassy carbon electrode, followed by the covalent immobilization of anti-troponin T antibodies by glutaraldehyde. Morphological and chemical characterizations of the nanohybrid film were performed by scanning electron microscopy and Fourier-transform infrared spectroscopy. Under the optimized conditions, a calibration curve for cTnT in spiked serum was obtained by square wave voltammetry, and a low limit of detection and quantification was achieved (0.35 and 1.05 pg mL−1, respectively). This was the first time that this type of nanohybrid film was used in the development of an immunosensor for cTnT that proved to be a simple and efficient strategy for the manufacture of a label-free electrochemical device that could be applied in the diagnosis of acute myocardial infarction.
