Portable, quantitative, real-time isothermal nucleic acid amplification test using microfluidic device-coupled UV-LED...

Area of Science:

• Biomedical Engineering
• Molecular Diagnostics
• Point-of-Care Testing

Background:

• Current molecular diagnostics often require complex laboratory infrastructure.
• There is a need for rapid, portable, and quantitative nucleic acid testing solutions for point-of-care applications.
• Existing point-of-care technologies may lack the sensitivity or specificity required for early disease detection.

Purpose of the Study:

• To develop and validate a novel, automated, and portable Microfluidics Integrated LED-Photodiode (MILP) sensing technology.
• To establish MILP as a quantitative molecular diagnostic platform for real-time nucleic acid testing.
• To assess the performance of the MILP device for SARS-CoV-2 detection.

Main Methods:

• Integration of a paper-based nucleic acid purification system with a polymer-based membrane filter.
• In-situ isothermal amplification and dual-mode optical detection.
• Quantitative signal analysis via photovoltaic response, electrical polarity, and photocurrent measurements.

Main Results:

• The MILP device achieved an on-cartridge limit of detection of 10 copies/μL.
• Demonstrated high clinical sensitivity (95%) and specificity (100%) for SARS-CoV-2 detection compared to real-time PCR.
• Quantitative photovoltaic cut-offs identified test-gene-specific variations without auxiliary instrumentation.

Conclusions:

• The MILP technology offers a stand-alone, fully quantitative, and portable solution for rapid molecular diagnostics.
• This platform is suitable for intensive health surveillance, early disease screening, and monitoring in resource-limited settings.
• The device eliminates the need for extensive and expensive laboratory infrastructure, facilitating widespread adoption.