Long-range and superfast trapping of DNA molecules in an ac electrokinetic funnel.
In this work we report a microfluidic platform capable of trapping and concentrating a trace amount of DNA molecules efficiently. Our strategy invokes nonlinear electro-osmotic flow induced by charge polarization under high-frequency ac fields. With the asymmetric quadrupole electrode design, a unique converging flow structure can be created for generating focusing effects on DNA molecules. This focusing in turn transforms into a robust funnel that can collect DNA molecules distantly from the bulk and pack them into a compact cone with the aid of short-range dipole-induced self-attraction and dielectrophoresis. Our results reveal that not only can DNA molecules be concentrated within just a few seconds, but also they can be focused into threads of 1 mm in length, demonstrating the superfast and long-range trapping capability of this funnel. In addition, pico M DNA solutions can be concentrated with several decades of enhancement without any continuous feeding. Alternating concentration and release of DNA molecules is also illustrated, which has potentials in concentrating and transporting biomolecules in a continuous fashion using microdevices.
Du
Jiong-Rong
JR
Department of Chemical Engineering and Center for MicroNano Science and Technology, National Cheng Kung University, Tainan 701, Taiwan.
Juang
Yi-Je
YJ
Wu
Jie-Tang
JT
Wei
Hsien-Hung
HH
Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics. 2000 Apr;61(4 Pt B):4019-28
11088193
Electrophoresis. 2003 Nov;24(21):3703-17
14613196
Anal Chem. 2005 Jul 15;77(14):4293-9
16013838
Phys Rev Lett. 1989 Nov 20;63(21):2373-2376
10040872
J Am Chem Soc. 2003 Oct 29;125(43):13026-7
14570466
Science. 1995 Jan 13;267(5195):219-22
7809626
Anal Chem. 2006 Jun 15;78(12):3887-908
16771530
Anal Chem. 2006 Jul 15;78(14):4976-84
16841920
Anal Chem. 2006 Jul 15;78(14):4779-85
16841895
Electrophoresis. 2004 Dec;25(23-24):4058-73
15597415
Electrophoresis. 2001 Jan;22(2):300-11
11288898
Anal Chem. 1999 May 1;71(9):1815-9
10330910
J Am Chem Soc. 2007 Jan 17;129(2):254-5
17212387
Proc Natl Acad Sci U S A. 2006 Mar 28;103(13):4825-30
16551750
Anal Chem. 2001 Nov 1;73(21):5088-96
11721904
Electrophoresis. 2005 Oct;26(19):3725-37
16136529
Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics. 2000 Apr;61(4 Pt B):4011-8
11088192