On-chip millionfold sample stacking using transient isotachophoresis
On-chip millionfold sample stacking using transient isotachophoresis
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DOI：
10.1021/ac051659w
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发表时间：
2006-04-01
影响因子：
7.4
通讯作者：
Santiago, JG
中科院分区：
文献类型：
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作者：
Jung, B;Bharadwaj, R;Santiago, JG
我们提出了一种简单而稳健的等速电泳（17W）方法，该方法可以与基于微芯片的毛细管电泳（CE）设备集成，以实现百万倍的样品堆叠。我们进行了实验参数研究，以显示初始样品离子浓度、超前离子浓度和尾随离子浓度对ITP堆积的影响。我们还讨论了一个简单的一维非色散模型和色散率的标度分析的有用性和局限性。我们发现单柱ITP结构加上电渗透流抑制和高铅离子浓度提供了高性能的ITP，并且可以很容易地与CE分离相结合。我们演示了100 fM Alexa Fluor 488（信噪比为11）的痕量检测，其浓度增加了2 × 10(6)。将我们的ITP/ CE协议应用于带负电荷的荧光示踪剂（Alexa Fluor 488和bodipy）的堆积和分离，导致浓度增加6.4 × 10(4)，信号增加4.5 × 10(5)。ITP/CE协议可以通过标准的微通道交叉设计或简单的流量控制来执行。该方法可以通过使用现成的电压控制系统和缓冲化学物质的现成芯片系统来实现。
We present a simple and robust isotachophoresis (17W) method that can be integrated with microchip-based capillary electrophoresis (CE) devices to achieve million-fold sample stacking. We performed an experimental parametric study to show the effects of initial sample ion concentration, leading ion concentration, and trailing ion concentration on ITP stacking. We also discuss the usefulness and limitations of a simple one-dimensional nondispersive model and a scaling analysis for dispersion rate. We found that a single-column ITP configuration together with electroosmotic flow suppression and high leading ion concentration provide high-performance ITP and can be integrated readily with CE separation. We demonstrated detection of trace of 100 fM Alexa Fluor 488 (signal-to-noise ratio of 11) with a concentration increase of a factor of 2 x 10(6). Application of our ITP/ CE protocol to the stacking and separation of negatively charged fluorescent tracers (Alexa Fluor 488 and bodipy) resulted in a concentration increase of 6.4 x 10(4) and a signal increase of 4.5 x 10(5). The ITP/CE protocol can be performed with a standard microchannel cross design or simple flow control. The method can be implemented with available off-the-shelf chip systems using off-the-shelf voltage control systems and buffer chemistries.