Department of Molecular Medicine, School of Medicine, Kyungpook National University, Daegu 41405, Republic of Korea.
DanielBio Research Center, Daegu 42694, Republic of Korea.
Biosensors (Basel). 2023 Jul 14;13(7):733. doi: 10.3390/bios13070733.
Hemagglutination assay has been used for blood typing and detecting viruses, thus applicable for the diagnosis of infectious diseases, including COVID-19. Therefore, the development of microfluidic devices for fast detection of hemagglutination is on-demand for point-of-care diagnosis. Here, we present a way to detect hemagglutination in 3D microfluidic devices via optical absorbance (optical density, OD) characterization. 3D printing is a powerful way to build microfluidic structures for diagnostic devices. However, mixing liquid in microfluidic chips is difficult due to laminar flow, which hampers practical applications such as antigen-antibody mixing. To overcome the issue, we fabricated 3D microfluidic chips with embedded microchannel and microwell structures to induce hemagglutination between red blood cells (RBCs) and antibodies. We named it a 3D microtrap chip. We also established an automated measurement system which is an integral part of diagnostic devices. To do this, we developed a novel way to identify RBC agglutination and non-agglutination via the OD difference. By adapting a 3D-printed aperture to the microtrap chip, we obtained a pure absorbance signal from the microchannels by eliminating the background brightness of the microtrap chip. By investigating the underlying optical physics, we provide a 3D device platform for detecting hemagglutination.
血凝检测法已被用于血型鉴定和病毒检测，因此可应用于传染病的诊断，包括 COVID-19。因此，开发用于快速检测血凝的微流控设备是即时诊断的需求。在这里，我们提出了一种通过光学吸光度（光密度，OD）特性来检测 3D 微流控设备中血凝的方法。3D 打印是构建诊断设备用微流控结构的一种强大方法。然而，由于层流的存在，微流控芯片中的液体混合变得困难，这阻碍了抗原-抗体混合等实际应用。为了解决这个问题，我们制造了具有嵌入式微通道和微井结构的 3D 微流控芯片，以诱导红细胞（RBC）和抗体之间的血凝。我们称之为 3D 微阱芯片。我们还建立了一个自动化测量系统，这是诊断设备的一个组成部分。为此，我们开发了一种通过 OD 差异识别 RBC 聚集和非聚集的新方法。通过将 3D 打印的光阑适配到微阱芯片上，我们通过消除微阱芯片的背景亮度，从微通道中获得了纯吸光度信号。通过研究潜在的光学物理，我们提供了一个用于检测血凝的 3D 设备平台。
