Division of Analytical Biosciences, LACDR, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands.
Anal Chem. 2011 Oct 15;83(20):7910-5. doi: 10.1021/ac2018348. Epub 2011 Sep 12.
Isotachophoretic separations are triggered at the border of a nanochannel-induced ion-depleted zone. This depletion zone acts as a terminating electrolyte and is created by concentration polarization over the nanochannel. We show both continuous and discrete sample injections as well as separation of up to four analytes. Continuous injection of a spacer compound was used for selective analyte elution. Zones were kept focused for over one hour, while shifting less than 700 μm. Moreover, zones could be deliberately positioned in the separation channel and focusing strength could be precisely tuned employing a three-point voltage actuation scheme. This makes depletion zone isotachophoresis (dzITP) a fully controllable single-electrolyte focusing and separation technique. For on-chip electrokinetic methods, dzITP sets a new standard in terms of versatility and operational simplicity.
等速电泳分离是在纳米通道诱导的离子耗尽区的边界处触发的。这个耗尽区充当终止电解质,是通过纳米通道上的浓差极化产生的。我们展示了连续和离散的样品注入以及多达四种分析物的分离。连续注入间隔物化合物用于选择性分析物洗脱。在一个多小时的时间里,区域保持聚焦,而只移动了不到 700μm。此外,可以通过三点电压激励方案故意将区域定位在分离通道中,并精确调整聚焦强度。这使得耗尽区等速电泳(dzITP)成为一种完全可控的单电解质聚焦和分离技术。对于芯片上的电动方法,dzITP 在多功能性和操作简单性方面树立了新的标准。