Development of fluidic system for electrochemical-based Covid-19 biosensor

Abstract

The global COVID-19 pandemic highlighted the need for rapid, point-of-care (POC) virus detection, particularly in remote and resource-limited settings. Conventional polymerase chain reaction (PCR) methods, while effective, have some limitations like requiring bulky equipment, expensive infrastructure, and complex procedures. This research addresses the PCR methods’ limitations by proposing a novel, portable biosensor system for POC DNA amplification detection using loop-mediated isothermal amplification (LAMP). This research focuses on developing three key components of the system which are a heating and temperature control system, device’s packaging, and its integrated fluidic device. A heating system that can maintain a stable temperature of 65°C is important for LAMP. Two types of heater controller systems were compared, the proportional-integral-derivative (PID) controller and the on-off controller. The device packaging was aimed to integrate all components in the system into a user-friendly compact and portable package. SolidWorks 2023 was used to design the entire packaging, housing for the biosensor, heater chamber, and heating circuit. The package was 3D printed using fused deposition modelling (FDM) technique. The packaging went through several iterations based on user feedback, leading to improvements in ergonomics and functionality. The fluidic device was fabricated using masked stereolithography apparatus (MSLA) 3D printing. This is to ensure precise control of sample flow and optimal interaction with the biosensor’s surface. The results demonstrate that the device reached a temperature stability of 65°C through the PID controller. The PID controller shows significantly better performance than the on-off controller, achieving a lower overshoot (1.9%) and steady-state error (0.3%) in maintaining the target temperature, ensuring optimal LAMP efficiency. The biosensor, heater chamber and heating circuit were successfully integrated into a compact and portable package. The fluidic channel with a diameter of 1.7mm was designed based on the reliable minimum printing resolution of MSLA. A flow rate of 3.2 μl/min was determined to achieve a 35-minute flow time over the heating area, achieving the LAMP reaction requirements. This work has contributed to the development of a portable biosensor system for POC virus detection particularly COVID-19 by developing a robust heating system with a precise temperature control, developing a user-friendly and portable device packaging, and optimizing a fluidic device for efficient LAMP amplification. In conclusion, this work holds considerable promise for revolutionizing POC virus detection, particularly in remote or resource-limited settings where access to laboratory facilities may be limited, and timely diagnosis is crucial for disease management and outbreak control.