Desenvolvimento de métodos eletroquímicos para diagnóstico rápido de virose bovina a partir de técnicas moleculares

Abstract

The bovine papillamatosis is a disease caused by papillomavirus that can generate damage for producers and farmers. In extreme cases it can affect all the herd. Diagnostic methods for bovine papillomavirus are essential to the sector because traditional methods of morphological observations are not very effective. The use of devices technological to recognize specific biological molecules may help treatment and prevention of bovine viral diseases. The biosensor incorporates a biological recognition element through electrochemical reactions that generate electrical signals that can be quantified and interpreted. Thus, this work aimed to develop molecular diagnostic methods for detection of bovine viral diseases through the construction of biosensors. One of the biosensor was constructed from pencil graphite type 4B and the other model biosensor was composed to three screen-printed electrodes. In both biosensors proposed, a DNA probe specific for the BPV was immobilized on the working electrode by electrodeposition or by adsorption and then a target sequence was hybridized with the probe immobilized. The hybridization redox signals were analyzed using differential pulse voltammetry. The results showed that biosensors could differentiate hybridization of non-hybridization. The hybridization occurrence showed decrease on the redox signal and represented the positive diagnostic for BPV infection. The two biosensors (pencil graphite and screen-printed electrodes) showed high sensitivity which detection limits were 3.84 nM and 4.35 nM, respectively. The biosensor also detected viral DNA extracted from bovine blood using screen-printed electrodes. The data obtained with the biosensors showed viability for the diagnosis of various bovine papillomavirus types, thereby allowing the development of a new portable detection system for viruses.