School of Information Science and Technology, ShanghaiTech University, Shanghai 201210, China.
State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China.
Biosensors (Basel). 2023 May 5;13(5):517. doi: 10.3390/bios13050517.
We developed a microfluidic chip integrated with nucleic acid purification and droplet-based digital polymerase chain reaction (ddPCR) modules to realize a 'sample-in, result-out' infectious virus diagnosis. The whole process involved pulling magnetic beads through drops in an oil-enclosed environment. The purified nucleic acids were dispensed into microdroplets by a concentric-ring, oil-water-mixing, flow-focusing droplets generator driven under negative pressure conditions. Microdroplets were generated with good uniformity (CV = 5.8%), adjustable diameters (50-200 μm), and controllable flow rates (0-0.3 μL/s). Further verification was provided by quantitative detection of plasmids. We observed a linear correlation of R = 0.9998 in the concentration range from 10 to 10 copies/μL. Finally, this chip was applied to quantify the nucleic acid concentrations of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The measured nucleic acid recovery rate of 75 ± 8.8% and detection limit of 10 copies/μL proved its on-chip purification and accurate detection abilities. This chip can potentially be a valuable tool in point-of-care testing.
我们开发了一种微流控芯片，集成了核酸纯化和基于液滴的数字聚合酶链反应 (ddPCR) 模块，实现了“样本进，结果出”的传染性病毒诊断。整个过程涉及在封闭的油环境中拉动磁珠通过液滴。纯化的核酸通过同心环、油水混合、流聚焦液滴发生器分配到微滴中，该发生器在负压条件下驱动。微滴具有良好的均匀性 (CV = 5.8%)、可调直径 (50-200μm) 和可控流速 (0-0.3μL/s)。通过质粒的定量检测进一步验证。我们观察到在浓度范围从 10 到 10 拷贝/μL 时，R = 0.9998 的线性相关性。最后，该芯片被用于定量检测严重急性呼吸综合征冠状病毒 2 (SARS-CoV-2) 的核酸浓度。75 ± 8.8%的测量核酸回收率和 10 拷贝/μL 的检测限证明了其片上纯化和准确检测能力。该芯片有望成为即时检测的有价值工具。
