DEVELOPMENT OF A PORTABLE DEVICE FOR LOOP-MEDIATED ISOTHERMAL AMPLIFICATION TEST FOR DETECTION OF PATHOGENS

• Autor(a) principal: Neca, Igor Campos
• Data de Publicação: 2023
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10362/160548
• topic: LAMP assay; DNA amplification; Portable device; Simulation; Instrumentation; Domínio/Área Científica::Engenharia e Tecnologia::Outras Engenharias e Tecnologias

Fecal contamination of soil and water in beaches and other recreational areas has been a persistent problem. Every year, approximately 120 million cases of gastrointestinal diseases and 50 million cases of severe respiratory infections caused by swimming and bathing in fecally polluted coastal waters are reported, directly impacting public health. Nowadays, there are several approaches to detect these pathogens, such as Polymerase Chain Reaction (PCR) and culture-based methods. However, most of these methods have long turnaround times between sample collection and obtaining results, and they often require a laboratory environment for execution. The Loop mediated isothermal amplification (LAMP) method stands out due to its remarkable sensitivity and specificity, enabling the detection of minute quantities of bacteria within a given sample. The objective of this study was to design and construct a portable device that could be used outside the laboratory. Simulations were carried out to ascertain the optimal approach for constructing the heating chamber, while additional simulation software was employed to enhance our comprehension of the electrical components necessary for building the circuit. A detailed inventory of these components is provided, along with the code developed for the microcontroller. Additionally, studies were conducted to assess power consumption, heating time, and temperature sensor calibration. A housing box for all the components was custom-designed using 3D printing technology. The LAMP assays were successful, validating the results of the aforementioned experiments. The code effectively enabled the microcontroller to read data from both temperature sensors, allowing for the adjustment of power delivered to the heating element. Furthermore, it accurately displayed relevant information on the heating chamber’s screen. Additionally, the code provided users with the ability to customize the assay duration, initiate and pause it, and appropriately illuminate LEDs to reflect the assay’s status. The researchwork described in this dissertationwas carried out in accordance with the norms established in the ethics code of Universidade Nova de Lisboa. The work described and the material presented in this dissertation, with the exceptions clearly indicated, constitute original work carried out by the author Igor Campos Neca.