Biochemical Science Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.
Anal Chem. 2009 Dec 15;81(24):10201-7. doi: 10.1021/ac902075c.
Sample-in answer-out analytical tools remain the goal of much lab on a chip research, but miniaturized methods capable of examining minimally prepared samples have proven elusive. Complex samples, including whole milk, various types of dirt and leaves, coal fly ash, and blood serum, were analyzed quantitatively for dissolved potassium, calcium, sodium, magnesium, lithium, and melamine using gradient elution moving boundary electrophoresis (GEMBE) and contactless conductivity detection with the single preparatory step of dilution or suspension in sample buffer. GEMBE is a simple, robust analytical technique, well-suited to microfluidic analysis of complex samples containing material, such as particulates or proteins, that would confound the majority of other microfluidic techniques. GEMBE utilizes electrophoretic flow to drive electrically charged analytes into a microfluidic channel or capillary for detection, while opposing electro-osmotic and variable pressure-driven flows prevent the remainder of the sample from entering the channel. Contactless conductivity detection further simplifies device construction and operation, positioning GEMBE for inexpensive and facile multiplexed implementation outside laboratory settings.
样品进-产物出分析工具仍然是芯片实验室研究的目标，但能够检测经最小化处理的样品的小型化方法一直难以实现。使用梯度洗脱移动边界电泳（GEMBE）和非接触式电导检测，对包括全脂牛奶、各种类型的污垢和叶子、煤飞灰和血清等复杂样品进行了定量分析，以检测溶解的钾、钙、钠、镁、锂和三聚氰胺。样品缓冲液的稀释或悬浮是唯一的预处理步骤。GEMBE 是一种简单、强大的分析技术，非常适合于包含颗粒或蛋白质等物质的复杂样品的微流分析，而这些物质会干扰大多数其他微流技术。GEMBE 利用电泳流将带电分析物驱动到微流道或毛细管中进行检测，而反向的电渗流和可变压力驱动流则阻止样品的其余部分进入通道。非接触式电导检测进一步简化了设备的构建和操作，使 GEMBE 能够在实验室环境之外以低廉且简单的方式实现多路复用。
