Desenvolvimento de um dispositivo para quantificação de níveis de lactato com aplicação para detecção de risco de sepse

Abstract

Sepsis is the disease that kills the most worldwide and affects millions of people every year, it also has high mortality rates that are associated with delayed diagnosis due to the centralization and complexity of laboratory tests. Blood lactate is considered a biomarker to identify the risk of sepsis when added to the other criteria that make up the SEPSE-3 consensus widely adopted in the world. Currently, to detect this biomarker, laboratory structures, equipment, reagents, inputs and qualified professionals are required. This complexity delays the identification of the risk of sepsis and makes it difficult to monitor patients. Also, the lack of access to lactate testing in low to medium income countries goes beyond its absence in extra-hospital environments. Therefore, the availability and use of tests to detect lactate levels from portable point-of-care (POC) devices allows for a quick result that streamlines the decision-making process of healthcare professionals and impacts on the reduction in patients' morbidity and mortality rates. The present work refers to the development of a technological product developed in the context of the Professional Master's in Nursing in partnership with the Semiconductor Institute (ITT Chip), both belonging to UNISINOS. The research developed a device to detect the lactate level through enzymatic reaction and detection of an electrical signal with potential for application in the care of patients at risk of sepsis. In this work, six devices were produced through different design dimensions, using photographic paper substrate and silicon foil. Conductive materials such as Aluminum, Silver, Gold and Graphene Nanoparticles Paint were deposited on the substrates through methods of manual deposition, screen printing, printing, thermal transfer and microfabrication. All the constructions produced were characterized and subjected to electrical measurements to differentiate lactate concentrations by changing the electrical current detected by chronoamperometry from an oxidoreduction reaction. Devices built using the microfabrication method, using gold as a conductive material, showed a better ability to differentiate lactate concentrations based on the increase in the electric current in relation to the increase in lactate concentration. Thus, it is possible to prospect that, after a clinical validation study with biological samples, this technology will be applicable in the scenario of care for patients with suspected sepsis or other diseases considered time-dependent to detect serum lactate levels.