Wong Ieong, Ho Chih-Ming
Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, USA,
Microfluid Nanofluidics. 2009 Sep 1;7(3):291-306. doi: 10.1007/s10404-009-0443-4.
Fast advancements of microfabrication processes in past two decades have reached to a fairly matured stage that we can manufacture a wide range of microfluidic devices. At present, the main challenge is the control of nanoscale properties on the surface of lab-on-a-chip to satisfy the need for biomedical applications. For example, poly(dimethylsiloxane) (PDMS) is a commonly used material for microfluidic circuitry, yet the hydrophobic nature of PDMS surface suffers serious nonspecific protein adsorption. Thus the current major efforts are focused on surface molecular property treatments for satisfying specific needs in handling macro functional molecules. Reviewing surface modifications of all types of materials used in microfluidics will be too broad. This review will only summarize recent advances in nonbiofouling PDMS surface modification strategies applicable to microfluidic technology and classify them into two main categories: (1) physical approach including physisorption of charged or amphiphilic polymers and copolymers, as well as (2) chemical approach including self assembled monolayer and thick polymer coating. Pros and cons of a collection of available yet fully exploited surface modification methods are briefly compared among subcategories.
在过去二十年中，微纳加工工艺取得了快速进展，已达到相当成熟的阶段，使我们能够制造出各种各样的微流控设备。目前，主要挑战在于控制芯片实验室表面的纳米级特性，以满足生物医学应用的需求。例如，聚二甲基硅氧烷（PDMS）是微流控电路常用的材料，但其表面的疏水性会导致严重的非特异性蛋白质吸附。因此，当前的主要努力集中在表面分子特性处理上，以满足处理大分子功能分子的特定需求。综述微流控中使用的所有类型材料的表面改性内容过于宽泛。本综述将仅总结适用于微流控技术的抗生物污染PDMS表面改性策略的最新进展，并将其分为两大类：（1）物理方法，包括带电或两亲性聚合物及共聚物的物理吸附，以及（2）化学方法，包括自组装单分子层和厚聚合物涂层。在各子类别中简要比较了一系列现有但未充分利用的表面改性方法的优缺点。
