表面印迹聚合物及其在微流控器件中的应用

Surface-imprinted polymers in microfluidic devices

分子印迹聚合物是通过在模板存在下固化交联的聚合物制备的.在固化过程中,聚合物和模板间形成非共价键.这些非共价结合位点被"冻结"在交联的聚合物中,即使移去模板后也依然维持他们的形状.余下的空穴与模板的尺寸和形状一致,并且可以选择性地从流过的混合物中俘获模板物质.在近几十年中,分子印迹的领域由选择性俘获小分子扩展到处理各种类型的样品.分子印迹聚合物(MIP)被用于分析种类繁多的样品,比如金属离子、药物分子、环境污染物、蛋白、病毒以至整个细胞.本文中我们综述相对较新的领域——表面印迹,这是一种可以用来生成相对较大的生物相关模板的印迹方法.传统的整体印迹法是直接在固化前将模板加入预聚体中,因而不适用于那些大到无法从固化后的聚合物中扩散出来的物质.要仅在表面上生成结合位点,必须要使用特别的方法,由此产生的表面印迹技术解决了分离科学以及化学和生物化学监测的重要问题.将印迹聚合物植入微流控芯片,大大扩展了微流体技术的适用性.本文叙述表面印迹最新的进展以及不同的实施手段,以及它们在微流控器件中的应用.

Molecularly imprinted polymers are generated by curing a cross-linked polymer in the presence of a template.During the curing process,noncovalent bonds form between the polymer and the template.The interaction sites for the noncovalent bonds become ＂frozen＂ in the cross-linking polymer and maintain their shape even after the template is removed.The resulting cavities reproduce the size and shape of the template and can selectively reincorporate the template when a mixture containing it flows over the imprinted surface.In the last few decades the field of molecular imprinting has evolved from being able to selectively capture only small molecules to dealing with all kinds of samples.Molecularly imprinted polymers（MIPs） have been generated for analytes as diverse as metal ions,drug molecules,environmental pollutants,proteins and viruses to entire cells.We review here the relatively new field of surface imprinting,which creates imprints of large,biologically relevant templates.The traditional bulk imprinting,where a template is simply added to a prepolymer before curing,cannot be applied if the analyte is too large to diffuse from the cured polymer.Special methods must be used to generate binding sites only on a surface.Those techniques have solved crucial problems in separation science as well as chemical and biochemical sensing.The implementation of imprinted polymers into microfluidic chips has greatly improved the applicability of microfluidics.We present the latest advances and different approaches of surface imprinting and their applications for microfluidic devices.