Poly(oxyethylene) based surface coatings for poly(dimethylsiloxane) microchannels
Poly(oxyethylene) based surface coatings for poly(dimethylsiloxane) microchannels
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作者：
Hellmich, W;Regtmeier, J;Ros, A
微流控系统中表面性质的控制是成功的生物分析应用不可或缺的先决条件。聚（二甲基硅氧烷）（PDMS）的微流体装置受到生物分子的不必要的吸附和缺乏控制电渗流（电渗流）的方法的阻碍。在本文中，我们提出了不同的策略。用不同链长的聚（环氧乙烷）（POE）分子涂覆PDMS表面。天然PDMS表面预处理暴露于紫外线照射或氧等离子体，和POE-硅烷的共价键以及三嵌段共聚物（F108）的物理吸附进行了研究。接触角测量和原子力显微镜（AFM）成像显示POE-硅烷和F108到PDMS表面的均匀附着。在F108的情况下，不同的吸附机制，亲水性和疏水性PDMS进行了讨论。这些涂层在PDMS微通道中的电渗迁移率的测定证明了它们用于电动力学应用的用途，在该电动力学应用中，电还原是不可避免的，并且蛋白质吸附必须被抑制。
Control of surface properties in microfluidic systems is an indispensable prerequisite for successful bioanalytical applications. Poly(dimethylsiloxane) (PDMS) microfluidic devices are hampered from unwanted adsorption of biomolecules and lack of methods to control electroosmotic flow (EOF). In this paper, we propose different strategies to. coat PDMS surfaces with poly(oxyethylene) (POE) molecules of varying chain lengths. The native PDMS surface is pretreated by exposure to UV irradiation or to an oxygen plasma, and the covalent linkage of POE-silanes as well as physical adsorption of a triblock-copolymer (F108) are studied. Contact angle measurements and atomic force microscopy (AFM) imaging revealed homogeneous attachment of POE-silanes and F108 to the PDMS surfaces. In the case of F108, different adsorption mechanisms to hydrophilic and hydrophobic PDMS are discussed. Determination of the electroosmotic mobilities of these coatings in PDMS microchannels prove their use for electrokinetic applications in which EOF reduction is inevitable and protein adsorption has to be suppressed.