Portable electroanalytical nucleic acid amplification tests using printed circuit boards and open-source electronics

Area of Science:

• Biotechnology
• Biosensor Technology
• Environmental Monitoring

Background:

• Electrochemical nucleic acid amplification tests (NAATs) are desirable for point-of-care (POC) diagnostics but are hindered by high costs and limited portability.
• Existing NAATs often require expensive components and complex thermal cycling equipment, restricting their widespread application.

Purpose of the Study:

• To develop a low-cost, portable electrochemical biosensor system for NAATs.
• To demonstrate the feasibility of using repurposed printed circuit boards (PCBs) as electrodes for DNA biosensing.
• To detect the toxic microalgae *Ostreopsis cf. ovata* as a proof of concept.

Main Methods:

• Utilized mass-produced PCBs as near-zero cost electrodes for self-assembled monolayer-based DNA biosensing.
• Integrated PCBs with a custom-designed, low-cost portable potentiostat.
• Developed a NAAT employing isothermal recombinase polymerase amplification (RPA) and electrochemical readout via a sandwich hybridization assay.

Main Results:

• Successfully repurposed industrial PCBs as functional electrodes for DNA biosensing.
• Demonstrated a low-cost, portable system capable of electrochemical NAATs without thermal cyclers.
• Achieved analytical detection of *Ostreopsis cf. ovata* DNA, validating the system's capability.

Conclusions:

• Repurposed PCBs and open-source electronics offer a viable pathway to low-cost, portable DNA biosensors for POC applications.
• The developed system significantly reduces the cost and complexity of NAATs.
• This approach holds potential for accessible environmental and health monitoring.