Microfluidic Lab-On-Chip for point of care infectious disease diagnostics

This work presents a microfluidic chip used to perform multiplexed analysis in order to diagnose infectious diseases at an early stage. This microfluidic approach uses two layers to attain a nanolitre scale compartmentalisation of the sample in four chambers requiring no pumps or valves. The device was designed using a 3D CAD software and fabricated by a stereolithography (SLA) 3D printer in a high temperature and transparent Polycarbonate-like material (Accura SL 5530). This design was experimentally validated by loading the sample solution within the fluidic channels under mineral oil. Surface wettability was ultimately investigated performing a contact angle evaluation according to the sessile-drop method. The microfluidic chip is integrated with a CMOS-based ion-sensitive field-effect transistor array able to quantify the presence of pathogens in a body fluid, monitoring the change of pH. This approach employs a molecular method diagnostic, the Loop-mediated isothermal amplification (LAMP), with the aim of monitoring the on-chip DNA amplification of pathogens. All components were emebedded in a motherboard for data acquisition and data analysis. This embedded system is expected to be extremely valuable to achieve a low-cost detection, a key aspect for point-of care (POC) tests especially in resource-limited settings.