Verma Abhilasha, Murray George M
Department of Mechanical, Aerospace and Biomedical Engineering, Center for Laser Applications, University of Tennessee Space Institute, 411 B.H. Goethert Parkway, Tullahoma, TN 37388, USA.
J Funct Biomater. 2011 Dec 23;3(1):1-22. doi: 10.3390/jfb3010001.
Molecular imprinting is a technique for making a selective binding site for a specific chemical. The technique involves building a polymeric scaffold of molecular complements containing the target molecule. Subsequent removal of the target leaves a cavity with a structural "memory" of the target. Molecularly imprinted polymers (MIPs) can be employed as selective adsorbents of specific molecules or molecular functional groups. In addition, sensors for specific molecules can be made using optical transduction through lumiphores residing in the imprinted site. We have found that the use of metal ions as chromophores can improve selectivity due to selective complex formation. The combination of molecular imprinting and spectroscopic selectivity can result in sensors that are highly sensitive and nearly immune to interferences. A weakness of conventional MIPs with regard to processing is the insolubility of crosslinked polymers. Traditional MIPs are prepared either as monoliths and ground into powders or are prepared in situ on a support. This limits the applicability of MIPs by imposing tedious or difficult processes for their inclusion in devices. The size of the particles hinders diffusion and slows response. These weaknesses could be avoided if a means were found to prepare individual macromolecules with crosslinked binding sites with soluble linear polymeric arms. This process has been made possible by controlled free radical polymerization techniques that can form pseudo-living polymers. Modern techniques of controlled free radical polymerization allow the preparation of block copolymers with potentially crosslinkable substituents in specific locations. The inclusion of crosslinkable mers proximate to the binding complex in the core of a star polymer allows the formation of molecularly imprinted macromolecules that are soluble and processable. Due to the much shorter distance for diffusion, the polymers exhibit rapid responses. This paper reviews the methods that have been employed for the trace determination of organophosphates in real world samples using MIPs.
分子印迹是一种为特定化学物质制造选择性结合位点的技术。该技术涉及构建一个包含目标分子的分子互补聚合物支架。随后去除目标分子会留下一个具有目标分子结构“记忆”的空腔。分子印迹聚合物（MIPs）可用作特定分子或分子官能团的选择性吸附剂。此外，可以利用驻留在印迹位点的发光体通过光学传感来制造特定分子的传感器。我们发现，由于选择性络合物的形成，使用金属离子作为发色团可以提高选择性。分子印迹和光谱选择性的结合可以产生高度灵敏且几乎不受干扰影响的传感器。传统MIPs在加工方面的一个弱点是交联聚合物的不溶性。传统的MIPs要么制成整体然后研磨成粉末，要么在载体上原位制备。这通过将繁琐或困难的过程用于将它们纳入器件中，限制了MIPs的适用性。颗粒的大小阻碍了扩散并减慢了响应速度。如果能找到一种方法来制备具有交联结合位点且带有可溶性线性聚合物臂的单个大分子，这些弱点是可以避免的。通过可形成假活性聚合物的可控自由基聚合技术，这个过程得以实现。现代可控自由基聚合技术允许制备在特定位置具有潜在可交联取代基的嵌段共聚物。在星形聚合物的核心中靠近结合复合物处包含可交联单体，可以形成可溶且可加工的分子印迹大分子。由于扩散距离短得多，这些聚合物表现出快速响应。本文综述了利用MIPs对实际样品中有机磷酸酯进行痕量测定所采用的方法。
