Desenvolvimento de biossensores eletroquímicos para detecção precoce e tratamento oportuno leishmaniose visceral humana em pacientes assintomáticos: novas fronteiras no combate à enfermidade

Abstract

This work describes the importance of electrochemical biosensors for the diagnosis of diseases. The central theme of the doctoral thesis presented is based on the description of a diagnostic methodology that refers to the development of an electrochemical biosensor for the detection of symptomatic and asymptomatic patients with leishmaniasis (LSH), which suppresses the cross-reaction with the disease leishmaniasis. Chagas (DC). It is a parasitic disease transmitted by infected mosquitoes. Its symptoms, often confused with other diseases, make accurate diagnosis difficult and delay the initiation of appropriate treatment. Therefore, it is necessary to develop an electrochemical biosensor that adequately detects even asymptomatic patients, and that maintains the predominant characteristics of this technique, such as excellent cost-benefit, fast execution and free from interference. Therefore, screen-printed graphite electrodes modified with graphene oxide were selected as platforms for the immobilization of raw Leishmania infantum total antigens. The electrochemical properties were evaluated by cyclic voltammetry (0.1 V.s-1). The ferri/potassium ferrocyanide redox couple made it possible to analyze the anodic and cathodic current peaks. Comparative analyzes with Indirect Enzyme Immunosorbent Assay (ELISA) were carried out with the same groups of patients, under conditions similar to those developed in the electrochemical biosensor. As for the calibration curve, our results present a limit of detection (LOD) of 5.58 mg.mL-1. Therefore, this sensor may present itself as a promising device for an efficient and effective diagnosis of antibodies against Leishmaniasis, present in sera from symptomatic and possibly asymptomatic patients.