Abstract
We investigate the effect of the surface charge at channel entrances upon ion conductance, which has been overlooked in the study of nanofluidics. Nonlinear ion transport behaviors were observed in 20-nm thick nanochannels having opposite surface charge polarity on the entrance side-walls with respect to that in the nanochannel. The heterogeneous distribution of surface charge at the channel entrance functions as a parasitic diode, which can cause ion current saturation under high voltage biases. Such effect becomes crucial at low bath concentration at which the electric double layers originated from the bath sidewalls pinch off the channel entrance. The experimental results are clarified by theoretical calculations based on 2D Poisson–Nernst–Planck equations. With such strong effect on ionic conductance of nanochannels, the change of surface charge polarity at the entrance sidewalls may find applications in chemical and biological sensing.
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References
Aguilella-Arzo M, Aguilella VM, Eisenberg RS (2005) Computing numerically the access resistance of a pore. Eur Biophys J Biophy 34:314–322
Bourikas K, Kordulis C, Lycourghiotis A (2005) Differential potentiometric titration: development of a methodology for determining the point of zero charge of metal (hydr)oxides by one titration curve. Environ Sci Technol 39:4100–4108
Cheng LJ, Guo LJ (2007) Rectified ion transport through concentration gradient in homogeneous silica nanochannels. Nano Lett 7:3165–3171
Cheng LJ, Guo LJ (2009) Ionic current rectification, breakdown, and switching in heterogeneous oxide nanofluidic devices. ACS Nano 3:575–584
Cheng LJ, Guo LJ (2010) Nanofluidic diodes. Chem Soc Rev 39:923–938
Daiguji H, Yang PD, Majumdar A (2004) Ion transport in nanofluidic channels. Nano Lett 4:137–142
Hall JE (1975) Access resistance of a small circular pore. J Gen Physiol 66:531–532
Karnik R, Fan R, Yue M, Li DY, Yang PD, Majumdar A (2005) Electrostatic control of ions and molecules in nanofluidic transistors. Nano Lett 5:943–948
Karnik R, Duan CH, Castelino K, Daiguji H, Majumdar A (2007) Rectification of ionic current in a nanofluidic diode. Nano Lett 7:547–551
Läuger P (1976) Diffusion-limited ion flow through pores. Biochim Biophys Acta 455:493–509
Neumcke B (1970) Ion flux across lipid bilayer membranes with charged surfaces. Biophysik 6:231–240
Parks GA (1965) Isoelectric points of solid oxides solid hydroxides and aqueous hydroxo complex systems. Chem Rev 65:177–198
Peskoff A, Bers DM (1988) Electrodiffusion of ions approaching the mouth of a conducting membrane channel. Biophys J 53:863–875
Plecis A, Schoch RB, Renaud P (2005) Ionic transport phenomena in nanofluidics: experimental and theoretical study of the exclusion-enrichment effect on a chip. Nano Lett 5:1147–1155
Pu QS, Yun JS, Temkin H, Liu SR (2004) Ion-enrichment and ion-depletion effect of nanochannel structures. Nano Lett 4:1099–1103
Schoch RB, Renaud P (2005) Ion transport through nanoslits dominated by the effective surface charge. Appl Phys Lett 86:25311–25313
Stein D, Kruithof M, Dekker C (2004) Surface-charge-governed ion transport in nanofluidic channels. Phys Rev Lett 93:4–7
Vlassiouk I, Siwy ZS (2007) Nanofluidic diode. Nano Lett 7:552–556
Acknowledgment
This work was supported by a Riethmiller Fellowship and the NSFC (grant no. 60528003).
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Cheng, LJ., Guo, L.J. Entrance effect on ion transport in nanochannels. Microfluid Nanofluid 9, 1033–1039 (2010). https://doi.org/10.1007/s10404-010-0621-4
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DOI: https://doi.org/10.1007/s10404-010-0621-4