Switchable pH actuators and 3D integrated salt bridges as new strategies for reconfigurable microfluidic free-flow electrophoretic separation
Switchable pH actuators and 3D integrated salt bridges as new strategies for reconfigurable microfluidic free-flow electrophoretic separation
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DOI：
10.1039/c3lc51023a
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发表时间：
2014-01-01
期刊：
影响因子：
6.1
通讯作者：
Chang, Hsueh-Chia
中科院分区：
文献类型：
--
作者：
Cheng, Li-Jing;Chang, Hsueh-Chia
我们提出了可重构的、高通量微流控自由流动电泳分离的新策略，使用可电切换的pH致动器和3D集成盐桥，以允许快速形成稳定的pH梯度和高效的电泳。PH致动器是通过双极膜的微流体集成实现的，双极膜通过在电压偏置时在膜结处注入过量的H+或OH-离子来改变电解液的pH，这些H+或OH-离子是由场增强的水解离现象产生的。该技术不需要传统的多次缓冲液流入，也不会像电解那样产生气体，从而为等电聚焦(IEF)分离提供稳定的pH梯度。在pH激励器失活的情况下，该平台可以在恒定pH的介质中进行区带电泳(ZE)分离。我们还描述了3D集成离子导电聚合物的使用，这些聚合物用作盐桥，以提高电泳的电压效率并允许高通量。概念验证成功地用于蛋白质混合物的自由流动IEF和ZE分离，显示了该平台在高通量和高精度样品分离方面的潜力和简单性。
We present novel strategies for reconfigurable, high-throughput microfluidic free-flow electrophoretic separation using electrically switchable pH actuators and 3D integrated salt bridges to allow rapid formation of stable pH gradients and efficient electrophoresis. The pH actuator is achieved by microfluidic integration of bipolar membranes which change electrolyte pH by injecting excess H+ or OH- ions produced by a field-enhanced water dissociation phenomenon at the membrane junction upon voltage bias. The technique does not require conventional multiple buffer inflows and leaves no gas production as experienced in electrolysis, thus providing stable pH gradients for isoelectric focusing (IEF) separation. With the pH actuator inactivated, the platform can perform zone electrophoretic (ZE) separation in a medium of constant pH. We also describe the use of 3D integrated ion conductive polymers that serve as salt bridges for improving the voltage efficiency of electrophoresis and to allow high throughput. The proof of concept was successfully demonstrated for free-flow IEF and ZE separation of protein mixtures showing the potential and the simplicity of the platform for high-throughput and high-precision sample separation.