Kanitthamniyom Pojchanun, Zhang Yi
Singapore 3D Printing Center, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore.
Electrophoresis. 2019 Feb 16. doi: 10.1002/elps.201900074.
Magnetic digital microfluidics uses magnetic force to manipulate droplets on a Teflon-coated substrate through the added magnetic particles. To achieve a wide range of droplet manipulation, hydrophilic patterns, known as surface energy traps, are introduced onto the Teflon-coated hydrophobic substrate. However, the Teflon-coated substrate is difficult to modify because it is nonwettable, and existing techniques for patterning surface energy traps have many limitations. Inspired by the mussel adhesion mechanism, we use polydopamine, a bioinspired substance that adheres strongly to almost any materials, to pattern surface energy traps on the Teflon-coated substrate with a great ease. We have optimized the polydopamine coating protocol and characterized the surface properties of the polydopamine surface energy traps. Droplet operations including particle extraction, liquid dispensing, liquid shaping, and cross-platform transfer have been demonstrated on the polydopamine surface energy trap-enabled magnetic digital microfluidic platform in both single-plate and two-plate configurations. Furthermore, the detection of hepatitis B surface antigen using ELISA has been demonstrated on the new magnetic dgitial microfluidic platform. This new bioinspired magnetic digital microfluidic platform is easy to fabricate and operate, showing a great potential for point-of-care applications.
磁性数字微流控技术利用磁力，通过添加的磁性颗粒在涂有特氟龙的基板上操纵液滴。为了实现广泛的液滴操纵，在涂有特氟龙的疏水基板上引入了称为表面能阱的亲水性图案。然而，涂有特氟龙的基板难以改性，因为它不可润湿，并且现有的用于图案化表面能阱的技术有许多局限性。受贻贝粘附机制的启发，我们使用聚多巴胺，一种能强烈粘附于几乎任何材料的仿生物质，轻松地在涂有特氟龙的基板上图案化表面能阱。我们优化了聚多巴胺涂层方案，并对聚多巴胺表面能阱的表面性质进行了表征。在单板和双板配置的基于聚多巴胺表面能阱的磁性数字微流控平台上，已经展示了包括颗粒提取、液体分配、液体成型和跨平台转移在内的液滴操作。此外，在新的磁性数字微流控平台上已经展示了使用酶联免疫吸附测定法检测乙型肝炎表面抗原。这种新型的仿生磁性数字微流控平台易于制造和操作，在即时检测应用中显示出巨大潜力。
