Laura InnesLaura InnesGraduate Students: Eric Kalman, Matt PowellGraduate Students: Eric Kalman, Matt Powell
Prof. Zuzanna SiwyProf. Zuzanna Siwy
Department of Physics and AstronomyDepartment of Physics and AstronomyUniversity of California, IrvineUniversity of California, Irvine
Looking at Single Molecules Looking at Single Molecules with Nanoporeswith Nanopores
Why are Nanopores Interesting?Why are Nanopores Interesting?
Biological channels are the basis of many physiological processes e.g. heart and muscle function and ‘wiring’ information from the brain to all the cells.
Nanopores are the basis for biosensors detecting single molecules
http://www1.engr.ucsb.edu/~saleh/Research/Saleh_Omar_Thesis.pdf
http://en.wikipedia.org/wiki/Cell_membrane
Making NanoporesMaking Nanopores
Creation of single nanopores starts at the GSI accelerator center in Darmstadt, Germany
Irradiated with a single ion of Au or U, at 2 GeV (15% c)
Deposition of energy from the swift, heavy ion creates a damage track in polymer
Chemical etching – ‘developing’ of the track created by single heavy ions
Gold Replica of a Single NanoporeGold Replica of a Single Nanopore
Scopece et al. Nanotechnology 17 (2006) 3951.
Formulas
Dd
LR
4
minmin/ 13.22 etchingtnmD
R – ionic resistance of a nanopore - specific conductivity of electrolyteL – membrane thickness
D
d
Structure of DendrimersStructure of Dendrimers
~3 nm
http://www.fda.gov/NANOTECHNOLOGY/powerpoint_conversions/chbsa-nanotech-presentation06-05_files/images/image4.png
H+
H+
Basic Physical Chemistry Basic Physical Chemistry of a Charged Particle in a Solutionof a Charged Particle in a Solution
ƒ F
ΔV - potential difference between two electrodes
l - distance apart
ƒ - frictional force
u - mobility of the ion
ze - charge
s - drift speed
l
VE
l
VzeF
uEs
af 6
Ff
a
zeu
6
When
2 a
There is a Voltage Threshold for the There is a Voltage Threshold for the Dendrimers to Enter a NanoporeDendrimers to Enter a Nanopore
-100 mV
-1000 mV
Future StudiesFuture Studies
current
time
• Continue to study the behavior of single molecules and nanopores
• Hopefully create an electromechanical valve