Modificações de eletrodos com nanomateriais para detecção de infarto agudo do miocárdio em biossensor eletroquímico

Abstract

Acute Myocardial Infarction (AMI) is a cardiovascular disease and is among the main causes of death worldwide. Patients who are seen in emergency rooms with suspected AMI undergo examinations of cardiac electrical activity and search for biomarkers of cardiac injury, usually troponins and creatine kinase. The detection of these biomarkers can be done using biosensors, analytical devices capable of converting a biological response into a signal of another nature. The objective of this work was to build an electrochemical biosensor using polymeric matrices enriched with nanomaterials, targeting biological markers for AMI. For this, the matrices were placed in contact with the surface of the electrodes and functionalization, through the deposition of the polymer, was induced through the passage of current. Subsequently, the modification was validated based on cyclic voltammetry readings. Through scanning electron microscopy, it was found that there was no change in the microscopic surface of the treated electrodes. However, the modification was able to improve the reading signal, increasing the active area, the current density and homogenizing the readings between the electrodes. Two analyte recognition strategies have been proposed, with variation in the biological layer assembly. The two strategies were able to differentiate positive from negative samples. The use of this methodology has advantages because the polymeric matrices are easy to obtain and the modification process simplified, in addition to being enriched with different materials. Ensuring that the efficient electrode functionalization step is essential for the construction of a biosensor, as it also guarantees that the deposition of the capture molecules takes place in a similar way with each repetition. The possibility of having a biosensor that uses few reagents is an advantage when it comes to practicality and low cost. Finally, nanomaterials associated with polymeric structures was an efficient way to stabilize and modify the surface of screen-printed electrodes and the platform developed here can be improved to become a clinical tool for the diagnosis of AMI.