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Screening Effect on Electric Field Produced by
Spontaneous Polarization in ZnO Quantum Dot in
Electrolyte
X. Meshika, M.S. Choib, M. Duttab,c, and M.A. Stroscioa,b,c
aDepartment
of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
bDepartment of Electrical & Computer Engineering, University of Illinois at Chicago, Chicago, IL 60607, USA
cDepartment of Physics, University of Illinois at Chicago, Chicago, IL 60607, USA
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ZnO quantum dots
c-axis
O2-
Zn2+
Material
Spontaneous
Polarization
AlN
-0.081 C/m2
InN
-0.032 C/m2
GaN
ZnO
BeO
-0.029 C/m2
-0.07 C/m2
-0.045 C/m2
Andrea Dal Corso, Michel Posternak, Raffaele Resta, and Alfonso Baldereschi, Ab initio study of piezoelectricity and spontaneous polarization in ZnO, Phys. Rev. B 50, 10715 (1994)
Fabio Bernardini‚ Vincenzo Fiorentini‚ and David Vanderbilt‚ Spontaneous polarization and piezoelectric constants of III-V nitrides‚ Phys. Review B56‚ R10024-R10127 (1997)
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Patch clamping
Extracellular fluid
ZnO
QD
5 mM K+
150 mM Na2+
2.5 mM Ca2+
125 mM Cl-
Amplifier
Cytoplasm
150 mM K+
15 mM Na2+
0.0001 mM Ca2+
5 mM Cl-
Voltage-gated ion channels
ZnO quantum dots
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Patch-clamp
Hodgkin-Huxley model
Cell membrane
Hodgkin AL, Huxley AF (1952) A quantitative description of membrane current and its application to
conduction and excitation in nerve. J Physiol 117:500-544.
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HH model of horizontal cells
Inside of the cell
Outside of the cell
Reeke, G. N. Modeling in the Neurosciences: From Biological Systems to Neuromimetic Robotics. Boca Raton, FL: Taylor & Francis, 2005. Print.
Usui, S., Kamiyama, Y., Ishii, H., and Ikeno, H. Reconstruction of retinal horizontal cell responses by the ionic current model. Vision Res. 36, 1711–1719, 1996.
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Ionic current in horizontal cells
5th-order Cash-Karp
Runge-Kutta method
Activation
With the presence of static-electric-field-producing quantum dots (e.g. ZnO QDs)
Inactivation
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Transient
outward K
current[1,2,5]
HH model Parameters in horizontal cells
Delayed
rectifying K
current[1,2,4,5]
3.0
-80
22.0
-80
4.5
-80
Ca current[4,5]
30.0
Leakage
current[1,5]
0.5
Anomalous
rectifying K
current[1,2,5]
Na current[1,5]
5.0
55
-80
[1] Reeke, G. N. Modeling in the Neurosciences: From Biological Systems to Neuromimetic Robotics. Boca Raton, FL: Taylor & Francis, 2005. Print.
[2] Tachibana, M. Ionic currents of solitary horizontal cells isolated from goldfish retina. J. Physiol. (Lond.) 345, 329–351, 1983.
[3] Cheng et. al. Intrinsic Light Response of Retinal Horizontal Cells of Teleosts. Nature. 460(7257) 899-903, 2009.
[4] Usui et. al. econstruction of retinal horizontal cell responses by the ionic current model. Vision Res. Jun, 36(12):1711-9, 1996.
[5] Min Choi*, Xenia Meshik*, Souvik Mukherjee, Sidra Farid, Sam Doan, Leigha Covnot, Robert P. Malchow, Mitra Dutta, and Michael A. Stroscio, Voltage
gating of retinal horizontal cells using UV-excited TiO2 nanoparticles, in press, 2015
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HH model of horizontal cells revisited
Inside of the cell
Outside of the cell
Reeke, G. N. Modeling in the Neurosciences: From Biological Systems to Neuromimetic Robotics. Boca Raton, FL: Taylor & Francis, 2005. Print.
Usui, S., Kamiyama, Y., Ishii, H., and Ikeno, H. Reconstruction of retinal horizontal cell responses by the ionic current model. Vision Res. 36, 1711–1719, 1996.
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ZnO quantum dots
c-axis
O2-
Zn2+
Material
Spontaneous
Polarization
AlN
-0.081 C/m2
InN
-0.032 C/m2
GaN
ZnO
BeO
-0.029 C/m2
-0.07 C/m2
-0.045 C/m2
Andrea Dal Corso, Michel Posternak, Raffaele Resta, and Alfonso Baldereschi, Ab initio study of piezoelectricity and spontaneous polarization in ZnO, Phys. Rev. B 50, 10715 (1994)
Fabio Bernardini‚ Vincenzo Fiorentini‚ and David Vanderbilt‚ Spontaneous polarization and piezoelectric constants of III-V nitrides‚ Phys. Review B56‚ R10024-R10127 (1997)
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Electric field from ZnO quantum dots
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Electric field from ZnO quantum dots
Electrolyte
Water
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Electrolyte with:
5 mM K+
150 mM Na2+
2.5 mM Ca2+
125 mM Cl2.5 nm
5.8 nm
7 nm
Results
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50 mV
40 mV
30 mV
20 mV
-100 mV
-110 mV
Shift of I-V curve
Inward rectifying
K+ channels
Voltage-gated Na+
and Ca2+ channels
Voltagegated K+
channels
Shift of I-V curve
Summary of result
• Considering that the minimum potential
difference needed to switch a voltagegated ion channel is about 6 mV1, which
requires the electric field across the 7 nm
membrane of about 0.86×106 V/m, ZnO
QDs should be within 5.8 nm of the cell.
• Both net peak and steady state ion current
I-V curves shifted due to the additional
potential from ZnO QD
• Individual ion channel currents are also
affected by the addition of ZnO QD
1. Stroscio, M. A., Dutta, M., Nariwani, K., Shi, P., Ramadurai, D. and Rufo, S. Integrating and Tagging
Biological Structures with Nanoscale Semiconducting Quantum-Dot Structures, in Michael A. Stroscio
and Mitra Dutta, editors, Biological Nanostructures and Applications of Nanostructures in Biology:
Electrical, Mechanical & Optical Properties, (Kluwer Academic Publishers, New York, 2004).
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Thank you!!