Department of Chemistry, Nanchang University, Nanchang, China.
J Chromatogr A. 2013 Jun 14;1294:145-51. doi: 10.1016/j.chroma.2013.04.022. Epub 2013 Apr 18.
A novel, simple, and economical method for the preparation of chiral stationary phases for chip-based enantioselective open tubular capillary electrochromatography (OT-CEC) using polydopamine (PDA) coating as an adhesive layer was reported for the first time. After the poly(dimethylsiloxane) (PDMS) microfluidic chip was filled with dopamine (DA) solution, PDA film was gradually formed and deposited on the inner wall of microchannel as permanent coating via the oxidation of DA by the oxygen dissolved in the solution. Due to possessing plentiful catechol and amine functional groups, PDA coating can serve as a versatile multifunctional platform for further secondary reactions, leading to tailoring of the coatings for protein bioconjugation by the thiols and amines via Michael addition or Schiff base reactions. Bovine serum albumin (BSA), acting as a target protein, was then stably and homogeneously immobilized in the PDA-coated PDMS microchannel to fabricate a novel protein stationary phase. Compared with the native PDMS microchannels, the modified surfaces exhibited much better wettability, more stable and enhanced electroosmotic mobility, and less nonspecific adsorption. The water contact angle and electroosmotic flow of PDA/BSA-coated PDMS substrate were measured to be 44° and 2.83×10(-4)cm(2)V(-1)s(-1), compared to those of 112° and 2.10×10(-4)cm(2)V(-1)s(-1) from the untreated one, respectively. Under a mild condition, d- and l-tryptophan were efficiently separated with a resolution of 1.68 within 130s utilizing a separation length of 37mm coupled with in-column amperometric detection on the PDA/BSA-coated PDMS microchips. This present versatile platform, facile conjugation of biomolecules onto microchip surfaces via mussel adhesive protein inspired coatings, may offer new processing strategies to prepare a biomimetic surface design on microfluidic chips, which is promising in high-throughput and complex biological analysis.
首次报道了一种新颖、简单、经济的方法，用于通过聚多巴胺 (PDA) 涂层作为附着层，在基于芯片的对映选择性开管毛细管电色谱 (OT-CEC) 中制备手性固定相。在聚二甲基硅氧烷 (PDMS) 微流控芯片中充满多巴胺 (DA) 溶液后，PDA 膜通过溶液中溶解的氧气氧化 DA，逐渐在微通道内壁上形成并沉积，成为永久性涂层。由于 PDA 涂层具有丰富的儿茶酚和胺官能团，因此它可以作为一个通用的多功能平台，通过迈克尔加成或席夫碱反应，用于通过硫醇和胺进一步进行二次反应，从而对涂层进行修饰，以用于蛋白质生物缀合。牛血清白蛋白 (BSA) 作为目标蛋白，然后被稳定且均匀地固定在 PDA 涂层的 PDMS 微通道中，以制造新型蛋白质固定相。与原始 PDMS 微通道相比，改性表面的润湿性更好，电渗流迁移率更稳定且增强，非特异性吸附更少。与未经处理的 PDMS 相比，PDA/BSA 涂层 PDMS 基底的水接触角和电渗流分别为 44°和 2.83×10(-4)cm(2)V(-1)s(-1)，而 112°和 2.10×10(-4)cm(2)V(-1)s(-1)。在温和条件下，通过在 PDMA/BSA 涂层 PDMS 微芯片上进行柱内安培检测，在 37mm 的分离长度下，d-和 l-色氨酸在 130s 内实现了 1.68 的有效分离。本研究中，这种多功能平台通过贻贝粘蛋白启发的涂层在手性微芯片表面上方便地进行生物分子偶联，为在微流控芯片上制备仿生表面设计提供了新的处理策略，有望在高通量和复杂的生物分析中得到应用。
