Han Bingyan, Xu Yuanhong, Zhang Lixue, Yang Xiurong, Wang Erkang
State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences, Changchun, Jilin 130022, China.
Talanta. 2009 Aug 15;79(3):959-62. doi: 10.1016/j.talanta.2009.04.030. Epub 2009 Apr 24.
This paper described a double-chained cationic surfactant, didodecyldimethylammonium bromide (DDAB), for dynamic surface modification of poly(dimethylsiloxane) (PDMS) microchips to reduce the fluorescent dyes adsorption onto the microchannel. When DDAB with a high concentration was present as the dynamic modification reagent in the running and sample buffer, it not only reversed the direction of electroosmotic flow, but also efficiently suppressed fluorescent dyes pyronine Y (PY) or rhodamine B (RB) adsorption onto the chip surface. In addition, vesicles formed by DDAB in the buffer with higher surface charge density and electrophoretic mobility could provide wider migration window and potential for the separation of compounds with similar hydrophobicity. Factors affecting modification, such as pH and concentrations of the buffer, DDAB concentration in the buffer were investigated. Compared with commonly used single-chained cetyltrimethylammonium bromide, DDAB provided a better modification performance. Furthermore, PY and RB were separated successfully on a PDMS microchip at the appropriate conditions with DDAB.
本文描述了一种双链阳离子表面活性剂——双十二烷基二甲基溴化铵（DDAB），用于聚二甲基硅氧烷（PDMS）微芯片的动态表面改性，以减少荧光染料在微通道上的吸附。当高浓度的DDAB作为动态改性试剂存在于运行缓冲液和样品缓冲液中时，它不仅能反转电渗流的方向，还能有效抑制荧光染料吡罗红Y（PY）或罗丹明B（RB）在芯片表面的吸附。此外，DDAB在具有更高表面电荷密度和电泳迁移率的缓冲液中形成的囊泡，可为分离具有相似疏水性的化合物提供更宽的迁移窗口和分离潜力。研究了影响改性的因素，如缓冲液的pH值和浓度、缓冲液中DDAB的浓度。与常用的单链十六烷基三甲基溴化铵相比，DDAB具有更好的改性性能。此外，在适当条件下使用DDAB，PY和RB在PDMS微芯片上成功实现了分离。
