Portal de Periódicos da CAPES

Chromatographic separations in a nanocapillary under pressure-driven conditions

2008; Elsevier BV; Volume: 1200; Issue: 2 Linguagem: Inglês

10.1016/j.chroma.2008.05.088

1873-3778

Xiayan Wang, Jianzheng Kang, Shili Wang, Joann J. Lu, Shaorong Liu,

Microfluidic and Bio-sensing Technologies

We report a unique property of nanocapillaries for chromatographic separations of ionic species. Due to the electric double layer overlap, ions are unevenly distributed inside a nanochannel, with counterions enriched near the wall and co-ions concentrated in the middle of the channel. As a pressure-driven flow is induced, the co-ions will move faster than the counterions. This differential transport results in a chromatographic separation. In this work, we introduce the fundamental mechanism of this separation technology and demonstrate its application for DNA separations. An outstanding feature of this technique is that each separation consumes less than 1 pL sample and generates less than 0.1 nL waste. We also apply this technique for separations of DNA molecules, and efficiencies of more than 100 000 plates per meter are obtained.