一种直接测定微流控芯片电渗流速度的新方法

随着微芯片技术的成熟,越来越迫切地需要有一个准确而简洁的电渗流速度的检测方法。根据荧光物质罗丹明123（Rh123）在不同pH缓冲溶液中迁移时间的变化,推导出Rh123在pH 9和10条件下分别有中性分子存在，而中性分子的移动速度等于电渗流速度,因此建立了直接以Rh123中性分子为标记物测定电渗流速度的方法。通过直接检测Rh123中性分子的迁移时间,计算得出所用玻璃微流控芯片在pH 9.3和pH 10.1的电渗流速度为3.9×10-4 cm2/(s·V)和4.1×10-4 cm2/(s·V),与经典方法对照无明显差异。

A Novel Method for the Direct Measurement of Electroosmotic Flow Velocity on Microfluidic Chips

As microfluidic technologies mature, accurate methods for the measurement of electroosmotic flow velocity on microfluidic chips are becoming increasingly important. A change of migration time of Rhodamine 123 (Rh123) at different pH values of the buffer was observed during the electrophoresis, and it was deduced that there is uncharged molecular form of Rh123 in alkaline solution because of deprotonation. Therefore, a method of direct measurement of electroosmotic flow velocity on microfluidic chip was developed based on the detection of migration time of the uncharged Rh123, because the migration speed of uncharged molecule is equal to the electroosmotic flow velocity. The electroosmotic flow velocity of glass microchip at pH 9.3 and 10.1 of the buffer was detected to be 3.9 x 10(-4) cm2/(s V) and 4.1 x 10(-4) cm2/(s V), respectively, which were in agreement with those obtained by the traditional method.