Métodos diagnósticos para o vírus Zika: genossensor eletroquímico baseado em nanocompósito polimérico e plataforma óptica e colorimétrica usando nanopartículas de ouro e prata

Abstract

The present work describes the development of electrochemical genossensor with graphite electrodes modified with reduced graphene oxide and polythiramine to detect the gRNA of Zika virus (ZIKV) and optical and colorimetric genosensor based on gold and silver nanoparticles. Zika virus (ZIKV) infection has become an emerging global health issue since the 2015 outbreak in Brazil. Since then the virus has spread to other countries in Latin America and the in United States. The control and monitoring of ZIKV infection are limited due to the unavailability of drugs, vaccines and rapid diagnosis. The most commonly used diagnostic test is the reverse transcriptase (RT-PCR) technique, which consists of a laborious method and can lead to indeterminate results. The present study evaluated the electrochemical, colorimetric and optical response of Zika virus gRNA samples from 10 infected patients wich were previously validated by the traditional RT-PCR method. The GE/rGO /Polytir platform showed superiority in electronic transfer and increased surface area when compared to GE without modification. The ZIK1V probe was immobilized on the GE/rGO/Polytir platform and the virus genomic material was detected by monitoring the electrochemical changes of the redox pair [Fe(CN)6]4/[Fe(CN)6]3 by differential pulse voltammetry. The analytical parameters were analyzed and the electrochemical genossensor showed detection limit of 10 fg/mL with current response decreasing less than 20% in the evaluated period of 90 days. In the optical and colorimetric platform the thiolated probe was immobilized followed by hybridization with target, spectrophotometer reading and visual changes of color. The platform was sensitive to variations in genetic material concentration and response decreasing less than by 5% in 90 days. Thus, the platforms developed here demonstrated efficient and cost-effective solutions in infection control and fills the gap of lack of diagnostic methods for the Zika virus.