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Published on: November 21, 2023
A sample-to-answer DNA detection microfluidic system integrating sample pretreatment and smartphone-readable gradient
Zengming Zhang1, Shuhao Zhao1, Lei Jiang1
1State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University No. 99, Yanxiang Road, Xi'an, 710054, P. R. China. ncpeng@mail.xjtu.edu.cn.
This study presents a novel microfluidic system for rapid and cost-effective DNA quantification, integrating sample preparation and smartphone-readable continuous-flow PCR (CF-PCR). The system achieves sample-to-answer detection in under 40 minutes, offering a promising solution for decentralized diagnostics.
Area of Science:
- Biotechnology and Biomedical Engineering
- Molecular Diagnostics
- Microfluidics
Background:
- Traditional full-process polymerase chain reaction (PCR) analysis is hindered by complex workflows, lengthy analysis times, and high equipment expenses.
- There is a need for simplified, rapid, and cost-effective nucleic acid detection methods, especially for decentralized and low-resource settings.
Purpose of the Study:
- To design and optimize an integrated microfluidic system for rapid DNA quantification.
- To combine sample pretreatment and smartphone-readable gradient plasmonic photothermal (GPPT) continuous-flow PCR (CF-PCR) into a single system.
- To reduce the cost and complexity of PCR analysis for improved accessibility.
Main Methods:
- Development of a microfluidic chip integrating sample pretreatment using immiscible reagents and magnetic bead (MB) manipulation for DNA purification and concentration.
- Integration of a gold nanorod (AuNR)-doped PDMS submodule for continuous-flow PCR (CF-PCR) utilizing the plasmonic photothermal effect for thermal gradient formation.
- Smartphone-based fluorescence detection for real-time monitoring and quantification.
Main Results:
- Successful purification and concentration of 100 μL plasma to 20 μL within 14 minutes with 69% DNA extraction efficiency.
- Demonstration of smartphone-based fluorescence CF-PCR with a dynamic linear range of 1.2 × 10^1 to 1.2 × 10^6 copies/μL.
- Completion of sample-to-answer HBV-DNA quantification in approximately 37 minutes, at <15% of commercial instrument cost.
Conclusions:
- The developed microfluidic system effectively integrates sample pretreatment, CF-PCR, and result characterization into a rapid, standardized, and low-cost workflow.
- The system's simplicity, speed, and affordability make it highly suitable for applications in decentralized laboratories and resource-limited environments.
- This approach significantly bridges the gap in accessible and efficient nucleic acid detection.
