Jeon Jaehyung, Park Chanyong, Ponnuvelu Dinesh Veeran, Park Sungsu
School of Mechanical Engineering, Sungkyunkwan University, Seoburo 2066, Jangan-gu, Suwon 16419, Korea.
Department of Biomedical Engineering, Sungkyunkwan University, Suwon 16419, Korea.
Diagnostics (Basel). 2021 May 28;11(6):977. doi: 10.3390/diagnostics11060977.
Despite the potential in fabrication of microfluidic paper-based analytical devices (μPADs) for point-of-care testing (POCT) kits, the development of simple, accurate, and rapid devices with higher sensitivity remains challenging. Here, we report a novel method for 3D-μPAD fabrication with enclosed channels using vat photopolymerization to avoid fluid evaporation. In detail, height of the enclosed channels was adjusted from 0.3 to 0.17 mm by varying the UV exposure time from 1 to 4 s for the top barrier, whereas the exposure time for the bottom and side barriers was fixed. As a result, sample flow in the enclosed channels of 3D-μPADs showed lesser wicking speed with very scant evaporation compared to that in the hemi channels in the 3D-μPADs. The stoppage of evaporation in the enclosed channels significantly improved the gray intensity and uniformity in the detection zone of the 3D-μPADs, resulting in as low as 0.3 mM glucose detection. Thus 3D-μPADs with enclosed channels showed enhanced sensitivity compared to the 3D-μPADs with hemi channels when dealing with a small volume sample. Our work provides a new insight into 3D-μPAD design with enclosed channels, which redefines the methodology in 3D printing.
尽管微流控纸基分析设备（μPADs）在即时检测（POCT）试剂盒制造方面具有潜力，但开发简单、准确、快速且灵敏度更高的设备仍然具有挑战性。在此，我们报告一种使用光固化3D打印制造具有封闭通道的3D-μPAD的新方法，以避免液体蒸发。具体而言，通过将顶部屏障的紫外线照射时间从1秒变化到4秒，将封闭通道的高度从0.3毫米调整到0.17毫米，而底部和侧面屏障的照射时间保持固定。结果，与3D-μPAD中的半通道相比，3D-μPAD封闭通道中的样品流动显示出更小的毛细作用速度且蒸发极少。封闭通道中蒸发的停止显著提高了3D-μPAD检测区域的灰度强度和均匀性，实现了低至0.3 mM葡萄糖的检测。因此，在处理小体积样品时，具有封闭通道的3D-μPAD比具有半通道的3D-μPAD显示出更高的灵敏度。我们的工作为具有封闭通道的3D-μPAD设计提供了新的见解，重新定义了3D打印的方法。
