Photochemical Oxidation of Poly(dimethylsiloxane) Surface and Subsequent Coating with Biomimetic Phosphorylcholine Polymer

Abstract

As a material for fabricating biomicrosystem devices called lab-on-a-chip or micro total analysis system (μTAS), poly(dimethylsiloxane) (PDMS) has been widely used. Generally, the devices used in biological applications require some surface modification in order to control the hydrophilicity and nonspecific adsorption of biomolecules on their surfaces. However, it is difficult to achieve surface modification that remains sufficiently stable over long enough duration for use in PDMS microfluidic devices. In this paper, we report a simple but reliable method of applying a surface coating of biomimetic polymer to PDMS surfaces by the combinative use of photochemical surface oxidation by VUV irradiation and subsequent coating of phospholipid copolymer containing 2-methacryloyloxyethyl phosphorylcholine (MPC) and 3-methacryloxytriethoxysilane (METESi). The effectiveness of this coating process has been demonstrated by a significant reduction in the nonspecific adsorption of serum albumin and the formation of a micropatterned surface coating using a photomask.