Effect of the surface charge on ion transport through nanoslits

被引:136
作者
Schoch, RB [1 ]
van Lintel, H [1 ]
Renaud, P [1 ]
机构
[1] Ecole Polytech Fed Lausanne, Microsyst Lab, STI LMIS, CH-1015 Lausanne, Switzerland
关键词
FLOW-CONTROL;
D O I
10.1063/1.1896936
中图分类号
O3 [力学];
学科分类号
08 ; 0801 ;
摘要
A description of ion transport through geometrically defined nanoslits is presented. It is characterized by the effective surface charge density and was obtained by impedance spectroscopy measurements of electrolytes with different physicochemical properties. The fluid channels were fabricated in a Pyrex-Pyrex field assisted bonding process with an intermediate layer of amorphous silicon. The height of the nanoslits was defined by the 50 nm thickness of the amorphous silicon layer. Two microfluidic channels, containing electrodes for the characterization of the nanoslits, maintained fresh liquid on both sides of the nanoapertures. By changing the KCl concentration of the electrolyte, a conductance plateau (in log-log scale) was observed due to the dominance of the effective surface charge density, resulting in an excess of mobile counterions in the nanoslits at low salt concentrations. The effective surface charge density of the Pyrex nanoslits could be modified by changing the pH of the solution. It was verified that at higher pH values the nanoslit conductance increased. Field-effect experiments allowed changing the effective surface charge density as well. The polarity of the external voltage could be chosen such that the effective surface charge density was increased or decreased, resulting in a higher or lower nanoslit conductance. This regulation of ionic flow can be exploited for the fabrication of nanofluidic devices. (c) 2005 American Institute of Physics.
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页数:5
相关论文
共 11 条
[1]   Ion transport in nanofluidic channels [J].
Daiguji, H ;
Yang, PD ;
Majumdar, A .
NANO LETTERS, 2004, 4 (01) :137-142
[2]   Fabrication of silica nanotube arrays from vertical silicon nanowire templates [J].
Fan, R ;
Wu, YY ;
Li, DY ;
Yue, M ;
Majumdar, A ;
Yang, PD .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2003, 125 (18) :5254-5255
[3]   EFFECTS OF BUFFER PH ON ELECTROOSMOTIC FLOW-CONTROL BY AN APPLIED RADIAL VOLTAGE FOR CAPILLARY ZONE ELECTROPHORESIS [J].
HAYES, MA ;
KHETERPAL, I ;
EWING, AG .
ANALYTICAL CHEMISTRY, 1993, 65 (01) :27-31
[4]  
Hunter R.J., 1981, Zeta Potential in Colloid Science: Principles and Applications, V1st ed
[5]   Characterization of individual polynucleotide molecules using a membrane channel [J].
Kasianowicz, JJ ;
Brandin, E ;
Branton, D ;
Deamer, DW .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 1996, 93 (24) :13770-13773
[6]   Ion-beam sculpting at nanometre length scales [J].
Li, J ;
Stein, D ;
McMullan, C ;
Branton, D ;
Aziz, MJ ;
Golovchenko, JA .
NATURE, 2001, 412 (6843) :166-169
[7]   Surface conduction [J].
Lyklema, J .
JOURNAL OF PHYSICS-CONDENSED MATTER, 2001, 13 (21) :5027-5034
[8]  
MacDonald J.R., 1991, IMPEDANCE SPECTROSCO
[9]  
Morgan H., 2003, AC Electrokinetics: Colloids and Nanoparticles
[10]   Field-effect flow control for microfabricated fluidic networks [J].
Schasfoort, RBM ;
Schlautmann, S ;
Hendrikse, L ;
van den Berg, A .
SCIENCE, 1999, 286 (5441) :942-945