Estudo das interações entre peptídeos, eletrodos impressos e indicadores eletroquímicos utilizando métodos voltamétricos para desenvolvimento de imunosensores

Abstract

Introduction. The diseases premature diagnosis is of fundamental importance for the effectiveness of public health actions. Current laboratory methods, besides expensive, are not able to serve remotely or in laboratory-free areas. It creates the manly difficult to implement rapid and comprehensive response policies. Recently, several devices have been miniaturized, providing portable alternatives for the development of diagnostic tests in the form of biosensors. Among these, portable potentiostats associated with printed electrode technology stand out for their operational simplicity, low cost, and diversity of techniques and base materials for commercially available electrodes. The functionalization of these electrodes' surface with antibodies or antigens (natural or not), originates electrochemical immunoassays, able to recognize their target (antigen or antibody) in the most diverse biological materials. Objective. To study the surface interactions between electrode material, biomolecules and electrochemical indicators, to theoretically subsidize the construction of electrochemical immunoassay using peptide probes. Material and methods. In our study, we used mimetic peptides of parasite antigens from diseases Visceral Leishmaniasis, American Cutaneous Leishmaniasis, Strongyloidiasis, and Leprosy, obtained by the Phage Display method as probes for recognition of the corresponding IgGs in human serum samples. Two platforms were developed according to the study of the affinities between these peptides and the base material of the electrodes, gold or graphite. Results and conclusion. The results demonstrated success in the functionalization substantiated on gold-thiol bond and graphite-peptide-pyrazol interactions, with discrimination between samples positive for studied diseases and controls. In addition, a universal electrochemical indicator for peptide probes has been proposed for use in carbon-based electrodes.