层层自组装聚电解质用于聚二甲基硅氧烷/玻璃微流控芯片修饰的研究

Dynamic Modification of Poly(dimethylsiloxane)/Glass Microfluidic Channels with Self-assembly Polyelectrolyte Multilayers

首次将聚丙烯氯化铵和聚丙烯酸通过静电吸附作用层层组装于聚二甲基硅氧烷/玻璃芯片内部,修饰后的芯片电渗流(EOF)随pH值的变化较小,具有较好的重复性和稳定性,EOF在2周内的变化率为1.58%。该芯片已经用于牛血清白蛋白(BSA)和胰岛素(insulin)的分离,BSA和胰岛素在20 s内得到了有效的分离,修饰后的芯片对BSA和胰岛素的理论塔板数分别为4.99×104/m,1.69×105/m,分离度为2.17;而未修饰的芯片对BSA和胰岛素的理论塔板数分别为4.65×103/m,4.13×104/m,分离度为1.32。该修饰方法可以有效抑制蛋白的吸附和样品峰拖尾的现象。

A hydrophilic poly （dimethylsiloxane）/glass （PDMS/glass） microehip was prepared by a simple and reproducible coating procedure with polyelectrolyte multilayers. The microchannel of PDMS/glass chip was coated with a layer of poly-（ allylamine hydrochloride） （PAH） then with poly （arylie acid） （PAA）. It was found that the electroosmotic flow （EOF） of the modified chip varied relatively small with pH and exhibited good reproducibility and stability. The variation rate of EOF was 1.58% within 2 weeks. Experimental results showed that bovine serum albumin（BSA） and insu- lin could be efficiently separated by the modified chip within 20 s. The theoretical plates of the modified chip for BSA and insulin were 4. 99 × 10^4/m and 1.69 × 10^5/m, respectively, with a resolution of 2. 17, while those of unmodified chip were 4.65 × 10^3/m and 4. 13 × 10^4/m, respectively, with a resolution of 1.32. The modified chip can suppress efficiently the adsorption of protein and the tailing of sample peak.