Nanoimmunoassays for malaria diagnosis

• Autor(a) principal: Gomes, Inês
• Data de Publicação: 2018
• Outros Autores: Reis, Ana, Pereira, Eulália, Fortunato, Elvira, Prudêncio, Miguel, Franco, Ricardo
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: https://doi.org/10.25761/anaisihmt.141

The development of Rapid Diagnostic Tests (RDTs) for malaria diagnosis is an area of intense research. Here, we describe two nanoimmunoassays for malaria parasite detection; one based on agarose gel electrophoresis; and another employing lab-onpaper technology. Both nanoimmunoassays use gold nanoparticles (AuNPs) functionalized with 11-mercaptoundecanoic acid (MUA) or with the pentapeptide CALNN, and further conjugated with a monoclonal antibody (anti- PfHRP2) that specifically recognizes Plasmodium falciparum Histidine Rich Protein 2 (PfHRP2) antigen. The formation of AuNP-anti-PfHRP2 bionanoconjugates was confirmed by agarose gel electrophoresis, demonstrating that AuNP functionalization and mode of conjugation (by physiosorption or by chemical cross-linking) control antibody binding to AuNP. The agarose gel-based nanoimmunoassay showed that AuNP-MUA-anti- PfHRP2 bionanoconjugates could detect an antigen concentration of 12 μg/mL, one order of magnitude less than that detected by AuNPCALNN- anti-PfHRP2 bionanoconjugates (700 μg/mL). AuNP-MUA-anti-PfHRP2 bionanoconjugates were also shown to be effective for direct colorimetric detection of the antigen by Western Blot, eliminating the need for a secondary antibody. The lab-on-paper technology-based RDT was developed on a filter cellulose filter paper-based strip, eliminating the traditional plastic casing. The amount of bionanoconjugates, and the components in test and control lines were optimized. In the future, our goal is to apply this RDT in the analysis of clinical samples.