The influence of membrane ion-permselectivity on electrokinetic concentration enrichment in membrane-based preconcentration units

被引:74
作者
Hlushkou, Dzmitry [2 ]
Dhopeshwarkar, Rahul [3 ]
Crooks, Richard M. [4 ]
Tallarek, Ulrich [1 ,5 ]
机构
[1] Univ Marburg, Dept Chem, D-35032 Marburg, Germany
[2] Otto Von Guericke Univ, Inst Verfahrenstech, D-39106 Magdeburg, Germany
[3] Texas A&M Univ, Dept Chem Engn, College Stn, TX 77843 USA
[4] Univ Texas Austin, Dept Chem & Biochem, Austin, TX 78712 USA
[5] Univ Marburg, Dept Chem, D-35032 Marburg, Germany
关键词
D O I
10.1039/b800549d
中图分类号
Q5 [生物化学];
学科分类号
071010 ; 081704 ;
摘要
The performance of nanoporous hydrogel microplugs with varying surface charge density is described in concentrating charged analytes electrokinetically in a microfluidic device. A neutral hydrogel plug with a mean pore size smaller than the size of charged analytes acts as a simple size-exclusion membrane. The presence of fixed charges on the backbone of a nanoporous hydrogel creates ion-permselectivity which results in charge-selective transport through the hydrogel. This leads to the development of concentration polarization (CP) in the adjoining bulk electrolyte solutions under the influence of an applied electrical field. CP strongly affects the distribution of the local electrical field strength, in particular, in the vicinity of the hydrogel plug which can significantly reduce the concentration enrichment factors compared to the neutral hydrogel. A theoretical model and simulations are presented, together with experimental data, to explain the interplay of hydrogel or membrane cation-selectivity, electrical field-induced CP, and the distribution of the local electrical field strength with respect to concentration enrichment of negatively charged analytes at the cathodic membrane-solution interface.
引用
收藏
页码:1153 / 1162
页数:10
相关论文
共 57 条
[1]   Nonlinear Smoluchowski slip velocity and micro-vortex generation [J].
Ben, Y ;
Chang, HC .
JOURNAL OF FLUID MECHANICS, 2002, 461 :229-238
[2]   Sample filtration, concentration, and separation integrated on microfluidic devices [J].
Broyles, BS ;
Jacobson, SC ;
Ramsey, JM .
ANALYTICAL CHEMISTRY, 2003, 75 (11) :2761-2767
[3]   CORRELATION BETWEEN MESH SIZE AND EQUILIBRIUM DEGREE OF SWELLING OF POLYMERIC NETWORKS [J].
CANAL, T ;
PEPPAS, NA .
JOURNAL OF BIOMEDICAL MATERIALS RESEARCH, 1989, 23 (10) :1183-1193
[4]   Discrete solution of the electrokinetic equations [J].
Capuani, F ;
Pagonabarraga, I ;
Frenkel, D .
JOURNAL OF CHEMICAL PHYSICS, 2004, 121 (02) :973-986
[5]   Sample stacking revisited: A personal perspective [J].
Chien, RL .
ELECTROPHORESIS, 2003, 24 (03) :486-497
[6]   Protein transport through gold-coated, charged nanopores:: Effects of applied voltage [J].
Chun, KY ;
Mafé, S ;
Ramírez, P ;
Stroeve, P .
CHEMICAL PHYSICS LETTERS, 2006, 418 (4-6) :561-564
[7]   Protein transport in nanoporous membranes modified with self-assembled monolayers of functionalized thiols [J].
Chun, KY ;
Stroeve, P .
LANGMUIR, 2002, 18 (12) :4653-4658
[8]   Membranes and microfluidics: a review [J].
de Jong, J. ;
Lammertink, R. G. H. ;
Wessling, M. .
LAB ON A CHIP, 2006, 6 (09) :1125-1139
[9]   Electrokinetic concentration enrichment within a microfluidic device using a hydrogel microplug [J].
Dhopeshwarkar, R ;
Li, SA ;
Crooks, RM .
LAB ON A CHIP, 2005, 5 (10) :1148-1154
[10]   Transient effects on microchannel electrokinetic filtering with an ion-permselective membrane [J].
Dhopeshwarkar, Rahul ;
Crooks, Richard M. ;
Hlushkou, Dzrnitry ;
Tallarek, Ulrich .
ANALYTICAL CHEMISTRY, 2008, 80 (04) :1039-1048