Resistive Pulse Nanopore Sensing of Nanoparticles – Steps towards physical detection of viruses

• Autor(a) principal: André, Daniel António Martins
• Data de Publicação: 2022
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10362/143768
• topic: Nanoparticles; Virus; Resistive Pulse Sensing; Domínio/Área Científica::Engenharia e Tecnologia::Nanotecnologia

Molecular diagnostics (MDx) provides well established and highly sensitive assays for the detection of pathogens widely used in modern clinics. However, as the on-going pandemic of Covid-19 has shown MDx has number of limitations, when addressing the needs of population wide screening, such as slow speed, com-plexity of sample collection and handling, production and distribution of reagents and overall cost. Therefore, finding new approaches for the detection of viruses would be a great importance in the context of both current and future pandemics. One of these approaches is Resistive pulse sensing (RPS). RPS is characterization tech-nique that obtains information about physical properties of nanoparticles by analyzing the variation in ionic current caused by a particle when traversing a pore. In this study we have explored RPS for the detection and characterization of physical properties of nanoparticles with similar diameters to that of SARS-CoV-2 virus. First, we characterized different nanopore chip designs having several types and sizes of constrictions using polystyrene model particles to mimic viruses. We used various sizes and concentrations of particles, with different buffer compositions and electrical volt-ages. Thereafter exhaled breath condensate was evaluated as possible sample matrix and liposomes were ex-ploited as an alternative safe model system. Data was analyzed for the RPS pulse shapes and frequencies and for the success rate of different combinations of experimental settings. This characterization serves as an important basis for further development of the RPS based assays.