Nanotechnology by Kester Peters
Subject Area(s): Physical Science, General science
Associated Units: Nature of Science, Technology Applications, Electrical
Conductivity and Nanoscales
Lesson Title: Biosensors applications
Nanopipette use in the SICM*
Department of Physics, Department of Chemistry and Biochemistry, Biomolecular Science Institute,
th
Florida International University, 11200 SW 8 St., Miami, FL 33199, USA.
*SICM: Scanning Ion Conductance Microscope
1
Grade Level:
8-9
Time Required:
4hrs
Nanopipette technology has been proven to be a
label free biosensor capable of identifying DNA, proteins, cell
topography and voltage potential of the cell. The nanopipette can
include specific recognition elements for analyte discrimination
based on size, shape and charge density. Nanopipettes can be
precisely manipulated with submicron accuracy to study single cell
dynamics. Students will design a nanopipette biosensor and test it
for electrical conductivity. The second portion of the lesson will
focus on graphene and its electrical properties and applications.
Students learn about nanotechnology and how engineers can
harness the difference in how materials behave when small, and
to address the challenges to many industries. Students work in
teams to hypothesize and test whether graphene is an electrical
conductor or insulator. Students will build a simple circuit using
everyday items and create a graphene sample using soft pencil on
paper. Students will observe, extrapolate to broader applications
and present their ideas to the class.
Summary
Engineering connection
Nanotechnologies allow the digital world and the biological world to merge
and can therefore detect biological substances. Such “hybrid technology”
uses an analytical device to provide a digital signal when encountering
specific concentrations of a targeted substance. The biological material can
be from human tissues, microorganisms, organelles, cell receptors,
enzymes, antibodies, or nucleic acids, as examples. Since these devices are
detecting biological substances, they are known as biosensors. The
synthetic side of biosensors uses optical, electrochemical, thermometric, or
2
magnetic systems for sensing the designated biological substance. How
prevalent will biosensors become in our lives? Already, scientists are
coming up with biosensors which when implanted in your body could even
signal when you're getting sick - almost like the ‘check engine’ light in a car.
Engineering Category
This lesson will incorporate science and math concepts pertinent to
engineering. Engineering analysis and partial design will be implemented.
The Nano-Biosensing activities support engineering research on
innovative, transformative, and insightful applications that require use of
novel nano-scale bio-inspired engineering principles and approaches. This
category of engineering emphasizes research in the area of the monitoring,
identification and/or quantification of biological signals. The development
of novel principles and approaches will require highly collaborative
interactions between engineers, life scientists and experts in
nanotechnology, biomaterials, bioinformatics, and the chemical and
physical sciences.
Key Words
Nanotechnology, biosensors, nanopipette, fabrication, electrolyte,
conductors, ions, resistance Ohm’s Law, conductivity, capillarity, scanning
probe microscope (SPM), scanning ion conductance microscope (SICM).
Educational Standards (List 2-4)
State STEM Standard
MS-PS1-6. Undertake a design project to construct, test, and
modify a device that either releases or absorb thermal energy by
chemical processes. (The iterative process of testing the most
promising solutions and modifying what is proposed on the basis
3
of the test results leading to greater refinement and ultimately to
an optimal solution.)
MS-PS2-5. Conduct an investigation and evaluate the
experimental design to provide evidence that fields exist between
objects exerting forces on each other even though the objects are
not in contact.
Source: MS PS topics combined 6.12.14 6/17/2014. A Framework
for K-12 science education, June 2013.
ITEEA Standard
The Nature of Technology
Standard 1: Students will develop an understanding of the characteristics
and scope of technology.
Standard 2: Students will develop an understanding of the core concepts of
technology.
Standard 3: Students will develop an understanding of the relationships
among technologies and the connections between technology and other
fields of study.
Technology and Society
Standard 4: Students will develop an understanding of the cultural, social,
economic, and political effects of technology.
Standard 5: Students will develop an understanding of the effects of
technology on the environment.
4
Standard 6: Students will develop an understanding of the role of society in
the development and use of technology.
Standard 7: Students will develop an understanding of the influence of
technology on history.
Design
Standard 8: Students will develop an understanding of the attributes of
design.
Standard 9: Students will develop an understanding of engineering design.
Standard 10: Students will develop an understanding of the role of
troubleshooting, research and development, invention and innovation, and
experimentation in problem solving.
Abilities for a Technological World
Standard 11: Students will develop abilities to apply the design process.
Standard 12: Students will develop abilities to use and maintain
technological products and systems.
Standard 13: Students will develop abilities to assess the impact of
products and systems.
The Designed World
Standard 14: Students will develop an understanding of and be able to
select and use medical technologies.
NGSS Standards
SC.8.N.1.1
5
Define a problem from the eighth grade curriculum using appropriate
reference materials to support scientific understanding, plan and carry out
scientific investigations of various types, such as systematic observations
or experiments, identify variables, collect and organize data, interpret data
in charts, tables, and graphics, analyze information, make predictions, and
defend conclusions.
SC.912.P.8.12
Describe the properties of the carbon atom that make the diversity of
carbon compounds possible. (Application of Graphene)
SC.912.P.10.14
Differentiate among conductors, semiconductors, and insulators
SC.912.P.10.15
Investigate and explain the relationships among current, voltage,
resistance, and power
SC.912.P.10.20
Describe the measurable properties of waves and explain the relationships
among them and how these properties change when the wave moves from
one medium to another.
CCSS Standards
MAFS.912.N-Q.1.1
Use units as a way to understand problems and to guide the solution of
multi-step problems; choose and interpret units consistently in formulas;
choose and interpret the scale and the origin in graphs and data displays.
6
MAFS.912.N-Q.1.3
Choose a level of accuracy appropriate to limitations on measurement
when reporting quantities.
MAFS.912.S-ID.1.1
Represent data with plots on the real number line (dot plots, histograms,
and box plots).
MAFS.912.G-GPE.2.7
Use coordinates to compute perimeters of polygons and areas of triangles
and rectangles, e.g., using the distance formula.
LAFS.68.RH.2.4
Determine the meaning of words and phrases as they are used in a text,
including vocabulary specific to domains related to history/social studies.
LAFS.68.RH.3.7
Integrate visual information (e.g., in charts, graphs, photographs, videos, or
maps) with other information in print and digital texts.
Source: www.cpalms.org/Public/PreviewStandards/Preview/6158
Pre-Requisite Knowledge
Students should be familiar with Ohm’s Law as it is used to determine the
voltage resistance in the nanopipette cone section. Students must be
familiar with measurement and conversions with the use of scientific
notation. Conversions using the dimensional analysis will be as asset.
Learning Objectives
1. Students will design and fabricate a nanopipette using capillary tubes
made from borosilicate or quartz. Students will measure the
conductivity flow within the nanopipette biosensor.
7
2. Describe the common methods and models used in different field of
science and analyze the benefits and limitations of them.
3. Evaluate a scientific investigation using evidence of scientific thinking
and problem solving.
4. Interpret and analyze data to make predictions and defend
conclusions.
5. Students will learn about nanotechnology and graphene applications.
6. Students will explore how engineering can help society’s challenges.
Introduction/Motivation
Understanding the details of how viruses, bacteria and naturally
occurring and synthetic nanoparticles (NPs) interact and penetrate cell
membrane is essential in developing drug or gene delivery systems. Several
imaging methods have been used to study cellular uptake of NPs. Optical
microscopy and fluorescence optical microscopy remain as the most widely
used imaging methods. However, the optical methods are still difficult to
resolve features with dimensions of tens of nanometers. In addition, it is
difficult to differentiate the cellular structures inside the cell from the ones on
the cell membrane. Electron microscopies (EMs) have been used to reveal
the NPs at the cell surface and inside the cell. The spatial resolution of EM
is very high but the cells need to be fixed and dehydrated. To achieve higher
image contrast and resolution, metallic NPs are often used. Atomic force
microscopy (AFM) has also been used to image the distribution of NPs at
cell surfaces, however, it is only limited to cells with rigid surface because of
strong interactions between AFM probe and the sample. Therefore, new
imaging methods are needed to study the dynamical process of NPs
internalization with high spatial resolution.
8
Scanning ion conductance microscopy (SICM), a unique combination
of patch-clamp and scanning probe microscope (SPM) techniques, has been
invented for more than 20 years. Due to the continuous improvements in
feedback control system, SICM has emerged as a powerful tool for the
imaging and analysis of fragile, adhesive or responsive surfaces, such as
live cell membranes.
The SICM can reveal tens of nanometer scale
resolution topography imaging of living cell membranes, which is difficult to
reveal by fluorescence microscopy. The sample preparation is also much
simpler than EMs and living cell imaging is possible for long periods of time.
Recently, non-specific adsorbed virus like particles were visualized at COS7
cell membranes. The plasma membrane morphology change associated
with exocytosis were observed at the membranes of bovine chromaffin cells.
The dynamics of microvilli (membrane projections) assembly in various
epithelial and nonepithelial living cells have been revealed. SICM has also
resolved the location, structure and dynamics of single protein and protein
complex in the cell membrane. However, the cell surface morphology feature
triggered by NPs during endocytosis has not been reported.
Conjugated polymer nanoparticles (CPNs) are intrinsic fluorescent
materials that are fabricated by self-assembly of non-aqueous soluble pelectron conjugated polymers (CPs) in an aqueous solution. Owing to
excellent photophysical and biophysical properties, CPNs have attracted
much interest in live cell imaging, drug delivery and biosensing. Positively
charged CPNs can enter cells via various endocytosis pathways and the
surface properties of CPNs influence the cellular interaction and
subsequent entry. The hydrophobicity from the backbone and positive
charge from the side chain allow efficient interaction with the cell
membrane, which contains negatively charged proteoglycans and
9
hydrophobic membrane lipids. In order to achieve high cellular labeling,
sensing, and delivery efficiency, it is highly important to understand the
details of endocytosis processes of CPNs, including how CPNs interact
with the cell membrane by observing cell surface morphology changes.
This has been achieved through the fabrication of nanopipette as a
biosensor for the SPM.
Lesson Background and Concepts for Teachers
. Nanopipette characterization
From the SEM image, the half cone angle of the glass nanopipette is
about 2 degrees. Therefore, the pore diameter D can be calculated by a
simple equation:
𝐷=
(eq. S1)
2
𝜋𝑘𝑅𝑝𝑡𝑎𝑛𝜃
where κ is the conductivity of 1x PBS buffer (~1.55S/m) and Rp is the pore
resistance. From the pore resistance 0.16 GΩ (Figure S1D) and half cone
angle 2, the calculated pore diameter D is about 74 nm using eq. S1. The
calculated size is consistent with the SEM image
Source: P.B. Tiwari;L. Astudillo;J. Miksovska;X. Wang;W. Li;Y. Darici; J. He, Nanoscale 6 (2014) 10255-63
10
Fabricated nanopipette from Dr. He’s physics lab. FIU 2015. Below is a carbon
nanopipette.
11
A: Nanopipette biosensor students will fabricate. B: scanning the
topograghy of cells.
This is Sutter model 2000 used for fabricating borosilicate capillarity tubes.
• Nanopipette fabrication and characterization: Nanopipettes were
fabricated from borosilicate glass with filament (O.D. 1 mm, I.D. 0.58 mm,
BF100-58-15, Sutter Instruments, Novato, CA) using a CO2-laser-based
micropipette puller (P-2000, Sutter Instruments, Novato, CA) with the
following parameters: HEAT=275, FIL=4, VEL=50, DEL=225 and PUL=150.
The resulting pipette opening had a diameter in the range of 70-80 nm (see
supporting information S1). The prepared nanopipette was back-filled with
PBS and immersed in bath solution. An Ag/AgCl wire electrode was placed
inside the nanopipette and another Ag/AgCl pellet electrode was placed in
12
the bath solution. The measured ion current between two electrodes was
0.8-1.0 nA at a bias of 0.1V when the bath solution was 1PBS.
Borosilicate capillary tubes (cnwtc.en.alibaba.com)
13
Nanoscale
(Taken from Wikipedia the free encyclopedia).
A comparison of the scale of various biological and technological objects.
14
Source: H. J Kim, International Journal of Precision Engineering; Vol 10, 2009
Applications of Nanopipette and Biosensors
One grand challenge in current biology is to understand how individual cellular
molecules interact together to form a functioning living cell. This requires new
methods to image a live cell on the nanoscale. The scanned nanopipette can be
used to obtain high resolution noncontact images of the surface of live cells under
physiological conditions and has been used to develop a family of related
methods that allow mapping of cell function on the nanoscale, and hence allow
the relationship between cell structure and function to be probed. This is a
powerful method to bridge the current gap between high resolution structures of
15
individual molecular complexes and low resolution imaging of live cell structure
and function.
Source: D. Klenerman; Y. Korchev. Nanomedicine, Vol. No1, pages 107-114.
The emergence of conducting polymer nanostructures, with their important and
wide-ranging applications in sensors, displays and coatings, has not been
accompanied by an emergence of appropriate electrochemical nanoscale
characterization tools. Herein it is shown that nanopipettes, as implemented in
variants of the scanning ion conductance microscope, have the potential to
address numerous needs of the conducting polymer nanostructure community.
Specifically, nanopipettes can fabricate freestanding conducting polymer
nanowires, map electroactivity and conductivity, deliver doses of reagents with
nanoscale precision, perform highly localized cyclic voltammetry and characterize
ion flux from actuators. Additionally, nanopipette innovations already
demonstrated in biological and analytical fields – such as individually controlled
double-barreled nanopipette setups, voltage-controlled deposition and
functionalized surfaces – open the door to new approaches to conducting
polymer nanostructure fabrication and characterization.
Source: C. Laslau; D. Williams. Nanopipette application, polymer NP, Vol.37, # 9.
Sept 2012, page 1177.
Lesson
Nanopipette fabrication as a biosensor probe and its application as a sensing tool
for current detection.



Students will fabricate a nanopipette from a borosilicate capillary tube.
Students will build nanopipette probe and measure its diameter and its
voltage resistance (apply Ohm’s Law)
Students will use the nanopipette probe as a method of cancer biomarker
detection using the electrical current to detect antigen to antibody.
16
Materials
Quartz capillary tubes were originally chosen for the experiment because
the process and machines already existed which made creating
nanopipettes simple, as well as provide a solid surface for chemistry.
The choice of quartz though, meant that the surface held a negative charge
(the chemical structure of quartz is SiO2). This charge then helped create a
baseline for measurements (the cause of negative rectification), as well as
surface where electrostatic binding could be used to attract molecules (in
this case PLL) to its surface.
PLL
The quartz nanopipette is immersed in poly-L-lysine (PLL) for at least 10
min. PLL is a polymer composed of a number of lysines bonded together.
In the case of this experiment, the length of the polymer was on average
30,000-70,000 monomers. The PLL was used in part to dampen the effect
of the negative charge from the quartz, but its main purpose is to put amine
groups on the surface of the nanopipette.
During this time the positively charged PLL (because of the NH3 groups
which face both towards the surface and away) will be electrostatically
attracted to the negatively charged quartz surface, while also leaving some
NH2 and NH3 groups exposed. The PLL thus provides amine groups which
are then used for the next step of chemistry where a carboxylated polymer
is added.
New buffer (used for new chemistry)
Phosphate buffered saline (PBS), 137 mM NaCl, 2.7 mM KCl, 10 mM
sodium phosphate, 2 mM potassium phosphate monobasic and a pH of
7.4.
Old Buffer (used for old chemistry)
100mM KCl solution containing 2 mM of phosphate ions that stabilize the
pH at 7.
Sulfo-SMCC
Sulfosuccinimidyl-4-(N-maleimidomethyl)cyclohexane-1-carboxylate (SulfoSMCC) is a water-soluble, non-cleavable and membrane impermeable
crosslinker. In its structure it has an amine-reactive N-hydroxysuccinimide
(NHS ester) and a sulfhydryl-reactive group used as a cross linker to bind
17
antibodies to the quartz nanopipette. Since it is soluble in water, it can be
used in place of organic solvents which can disrupt protein structure.
Carboxylated polymer
In this experiment we used a proprietary solution that was provided to us,
but the main requirement is that it is a carbon chain where both ends have
carbonyl groups (COOH). The purpose of this is so that we can get an
exposed carboxyl group at the end of a carbon chain of set length, which is
then acted on by a EDC/NHS reaction.
Protein A/G
Protein A/G is a recombinant fusion protein which is useful because it binds
to all subclasses of human IgG, which means that it acts as a perfect
platform for sensing, because it can be used regardless of the antibody you
want to use. And so after the EDC/NHS reaction, the nanopipette is
suspended in a Protein A/G solution (concentration is 0.1 mg/ml) overnight
(16 hours). It is step 3 in the overall process shown in Figure 9.
IgG of choice, anti-VEGF and anti-IL-10 in this experiment
After sitting in the Protein A/G solution, the nanopipette is then immersed in
an antibody solution of choice (concentration 40 uM/L) for one hour. This
allows the antibodies time to bind to the Protein A/G. It is step 4 in the
overall process shown in Figure 9.
Preparing gel box
The old chemistry also used what was referred to as a gel box to allow
electrical signals to pass from electrode to electrode, without contaminating
the reference electrode. The gel box is made with 1% Agar mix with water.
The gel is poured into a box (an old pipette tip box was used), and after it
hardens, a layer of buffer is put over it to prevent it from drying out and
provide a bath where the antigens could float. For the new chemistry, we
forgo the use of the gel box, since sometimes the signal is not as stable
when it was in use. So for the time being, we refrained from using it and
simply cleaned the electrodes before each experiment using bleach.
Faraday cage
Used to protect the system from outer noise except during the addition of
target molecules when the cage had to be open. The time period where the
18
cage was open was compensated for by removal of the data from the
period of time when the cage was open.
Electrodes
Ag/AgCl wire electrode was inserted from the back of the nanopipette.
Signal Amplification Amplifier connected through a headstage (Axopatch
200B and CV 203BU; Molecular Devices)
Engage
Students will first view the You-Tube clip on biosensors and design a
graphic organizer of all their applications. Have a discussion on how
nanotechnology is changing society. Have students discuss any pros and
cons of the nano world. Have students write those pros and cons on sticky
notes and place on white board. Provide students with the first two pages
of the article (Functionalized nanopipettes: towards label free single cell
biosensors) published with open access at Springerlink.com June 2010
(authors: P. Actis; A. Mak; N. Pourmand). Use jump in reading or any other
appropriate reading strategies to dissect the text. Allow students to revisit
the graphic organizer and add to its content. Students must compare their
graphic organizers.
https://www.youtube.com/watch?v=D7uX2ureyb0&feature=player_detailpa
ge
Explore
Students will fabricate their own nanopipettes and produce a biosensor
probe.
Students will measure the nanopipette’s diameter and determine electrical
conductivity within its pore.
While they have a variety of potential uses, nanopipette tips can be very
fragile. As a result, nanopipettes have to be fabricated on-site through the
use of a machine designed to pull capillary tubes or filaments. This device
(a P-2000 laser puller by Sutter Instrument Co.) is used to pull a quartz
capillary tube, 1 mm outer diameter and 6 cm long, with a inner diameter of
19
0.70mm. Once the capillary tube is inserted into the machine, a CO2 laser
is applied to the center of the nanopipette as the two sides of the capillary
are pulled by the machine in opposite directions until the tips break apart
(Figure 4A, 4B). The result is a pair of nanopipettes, which have an inner
tip diameter of, on average, 50 nm (Figure 4C). The reason we chose our
parameters to result in nanopipettes around this size is because the tip is
small enough to provide as much sensitivity as possible without risk of
clogging.
PULL
PULL
A
CO2 Laser
B
Fig 4A and 4B
Physical properties of the nanopipette. Action involved in how a nanopipette is pulled by the
Sutter 2000 puller. This process can be done manually with a Brunson burner if equipment is
not available at the high school.
20
Procedure
A.) Pull quartz capillary tube using a Sutter P-2000 instrument pipette
puller.
B.) Immersion in poly-L-lysine (PLL) for at least 10 min.
C.) PLL is then attached to the surface by baking the nanopipettes for 2
hours at 120°C after being removed from PLL solution. This is so that the
PLL solution is securely attached to the surface during the experiment.
Immersion of the nanopipette is done by putting them into a pipette holder,
and inverting the nanopipette over the solution.
D.) Linking carboxylate solution: Nanopipette was left in solution for 10 min
to cover the surface with functional carboxylate groups. To prevent crosslinking with PLL, the nanopipette tip is oversaturated with the linking
carboxylate solution.
E.) Washed several times with water.
F.) Immersion in a 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide
hydrochloride (EDC) and N-hydroxysulfosuccinimide (NHS) solution. This
activates the surface by providing effective places for binding.
Concentration of the EDC/NHS solution was (50mg/ml each) and was
immersed for 1 hour.
G.) Washed several times with water.
H.) Immersion in a protein A/G solution, used for conjugation. It is a
chimeric protein that captures the Fc region of a IgG molecule so that the
appropriate antigen binding site is properly oriented. The concentration of
the Protein A/G solution was 0.1-mg/ml and kept still at 4 °C in a
refrigerator overnight (16 hours).
I.) Washed several times in water and then buffer.
J.) Immersion in buffer solution containing antibodies. Done for antibody
immobilization and attachment to the surface of the nanopipette. The
concentration of the solution was 40-ug/ml and lasted for 1 hour.
21
K.) The nanopipette is then filled with a buffer solution.
Diagram and image of the setup used to take measurements with the nanopipettes. The signal generated
from the nanopipettes goes through the headstage, and the signal is then amplified and converted into a
form that the computer can read and display to the user. The light blue box represents either a buffer bath
or gel box since they have the same purpose and function. The long grey oval is representative of the
reference electrode (which is the red wired electrode in the photograph). Images are copied from the
Pourmand lab nanopipette group
22
Procedure for taking measurements
A.) Fabrication of nanopipettes
* Pull nanopipettes
*Perform chemistry to attach antibodies to nanopipette tips
B.) Make sure gel box is prepared (ensure it did not dry out and still
contains buffer.
C.) Set up the Faraday cage and ensure there is no charge inside
D.) Insert the nanopipette over the electrode after injecting buffer into it
E.) Lower the nanopipettes into the buffer bath (each of which contain 300
ul) and the reference electrode into the other buffer bath.
F.) Turn on the PatchClamp software (version 9.2 was used in this case).
G.) General troubleshooting includes making sure the system is properly
zeroed, there are no bubbles in the tips of the nanopipettes which might
block signal or any other form of blockage in signal.
H.) Begin taking measurements at varying intensities (10mV increments 10
times, and then 100mV increments 10 times). And then based on those
results, choose a certain signal strength to use for the main experiment
(usually 200 or 500 mV).
I.) Main experiment
* Let the system run for one file (17 min)
* Add 40 uL of antigen to the solution and make sure they are dispersed
throughout the solution.
* Let the system run for at least two files (34 min) or longer, depending on
if a change is observed.
J.) If appropriate, look at the nanopipettes under a fluorescent microscope
K.) Analyze the data
23
Acquiring data
Record data while the nanopipettes sit in a PBS buffer bath with no
antigens present. The purpose of this is to get a standard and stable signal
before proceeding onto the antigen-containing bath, and when you have
seen a drop in current, you can be confident that it is due to the antigen,
not random variation or noise. Once a stable signal is achieved, the buffer
bath is replaced with one containing the antigens of interest and recording
begins again. The recording was allowed to continue until either 1 hour had
passed, or the signal leveled off after a change in current was observed
and remained at that level for 10 min.
Explain
Use the data collected to make analysis. The expected results included
recording a drop in current in the probe nanopipette, which had the
appropriate antigen added as the antibody on the nanopipette, and the
nanopipette with different antibodies (the control), would not see a drop in
current.
Results are based on a change in current passing through the tip of the
nanopipette, which would be a clear indicator that something is partially
obstructing the gap at the tip. A simple explanation for this is to compare
the current moving through the nanopipette with water moving down a pipe,
and if the water pipe becomes partially obstructed, you will have less water
coming out. These drops in current are easy to notice by observing the
outputted current with the human eye through Clampex 9.2 software, or it
can be made clearer when the results are normalized to where the current
value of a stable signal is made equivalent to 1. This allows you to see the
average signal before the addition of the antigen and the subsequent
marked drop in current after addition.
Discussion
Read the following article on nanotechnology and answer the questions
that follow in your groups. (Use graphic organizers on a flip chart to display
your group’s ideas).
24
Nanoshells cancer treatment proves effective in first animal test
22 Jun 2004 A revolutionary new form of cancer therapy in development at
Rice University and its licensee, Nanospectra Biosciences Inc., has proven
effective at eradicating tumors in laboratory animals during the first phase
of animal testing. The noninvasive cancer treatment uses a combination of
harmless, near-infrared light and benign, gold nanoshells to destroy tumors
with heat. The treatment does not affect healthy tissue. "We are extremely
encouraged by the results of these first animal tests," said Jennifer West,
Professor of Bioengineering and Chemical Engineering. "These results
confirm that nanoshells are effective agents for the photothermal treatment
of in vivo tumors." Results of the study are published in the June 25 issue
of the journal Cancer Letters. Invented in the 1990s by Naomi Halas at
Rice, nanoshells are about 20 times smaller than a red blood cell. The
multilayered nanoshells consist of a silica core covered by a thin gold shell.
The size, shape and composition of nanoshells give them unique optical
properties. By varying the size of the core and the thickness of the gold
shell, researchers can tailor a nanoshell to respond to a specific
wavelength of light. The photothermal cancer treatment uses nanoshells
that are tuned to respond to near-infrared light. Located just outside the
visible spectrum, near-infrared light passes harmlessly through soft tissue.
In the treatment, nanoshells convert this light into heat that destroys nearby
tumor cells. The heating is very localized and does not affect healthy tissue
adjacent to the tumor. The animal trial involved 25 mice with tumors
ranging in size from 3-5.5 millimeters. The mice were divided into three
groups. The first group was given no treatment. The second received saline
injections, followed by three minutes exposure to near-infrared laser light.
The final group received nanoshell injections and laser treatments. The
blood vessels inside tumors develop poorly, allowing small particles like
nanoshells to leak out and accumulate inside tumors. In the test,
researchers injected nanoshells into the mice, waited six hours to give the
nanoshells time to accumulate in the tumors and then applied a 5millimeter wide laser on the skin above each tumor. Surface temperature
measurements taken on the skin above the tumors during the laser
treatments showed a marked increase that averaged about 46 degrees
Fahrenheit for the nanoshells group. There was no measurable
temperature increase at the site of laser treatments in the saline group.
Likewise, sections of laser-treated skin located apart from the tumor sites in
25
the nanoshells group also showed no increase in temperature, indicating
that the nanoshells had accumulated as expected within the tumors. All
signs of tumors disappeared in the nanoshells group within 10 days. These
mice remained cancer-free after treatment. Tumors in the other two test
groups continued to grow rapidly. All mice in these groups were euthanized
when the tumors reached 10 millimeters in size. The mean survival time of
the mice receiving no treatment was 10.1 days; the mean survival time for
the group receiving saline injections and laser treatments was 12.5 days.
"The results of these first animal studies are very promising, and while we
don't yet have a target date for our first human trial, our entire team is
working hard to make this treatment available to cancer patients as soon as
possible," said Halas, the Stanley C. Moore Professor in Electrical and
Computer Engineering and Professor of Chemistry. "We have licensed the
technology to the Houston-based firm Nanospectra Biosciences Inc., which
will obtain the necessary approvals and funding for human trials."
Article Questions
Using information in the article, what is so unique about the gold
nanoshells?
Using a flow map/graphic organizer, document the procedure used
by the scientists to treat the cancer cells.
Assessment
1. What does SEM stand for and what does it use to image objects?
SEM stands for scanning electron microscope and it uses electrons to
image objects.
2. How does SEM compare to the light microscope?
Light microscopes use light and can image objects up to 1500x
magnification. The images are in color. Light microscopes can be used to
image living objects and wet samples. The scanning electron microscope
uses electrons and can image items smaller than the wavelength of light
including nanoscale objects. The pictures are not in color because light is
not used. SEM cannot image living objects and wet samples.
26
3. In a typical SEM, samples must be coated with carbon or metal, why is
this?
Samples are coated to make the sample conductive (attracts electrons).
4. What are some of the limitations of using SEM for imaging?
SEM cannot be used to image living organisms or wet samples because
the samples are under vacuum. Non-conductive samples require a
conductive coating which permanently alters the object. Size is also a
limitation - small samples are required. Images must be artificially colored
since they are not in color. A SEM is expensive and often requires
expertise to operate it.
5. What features are visible on objects when viewed under SEM as
compared in their macroscopic state (ex: pollen)? Patterns, pores, and
other surface features can be seen with SEM. For the pollen, the different
size and shapes are distinguishable with the SEM, but cannot be observed
with the unaided eye.
Test Your Nano IQ
Take the quiz to test your Nano IQ!
1. Which of these is at the nanoscale (between 1 and
100 nanometers)?
a. the head of a pin
snowflake
b. DNA
c. a red blood cell
d. a hydrogen atom
e. a
2. What are "bucky balls"?
a. a new form of elemental carbon, similar in structure to a geodesic dome
new, nano-enhanced soccer balls to be used at the 2010 World Cup
b.
c. an annual
27
gala for nanotechnologists
d. an extremely unstable nanoscale sphere that, due to
quantum mechanics, moves about erratically
3. Which of these products might contain
nanotechnology? *
a. sunscreen
slacks
b. an iPod
c. a teddy bear
d. tennis rackets
e. a pair of
f. all of the above
4. What type of nanomaterial is used in the widest
variety of nanotechnology products on the market
today, according to the Project's Consumer Products
Inventory?
a. silicon
b. silver
c. carbon
d. titanium dioxide
e. gold
5. Which are POSSIBLE risks of nanotechnology
today?
a. nanomachines might devour the world and turn everything into a "gray goo"
b.
nano-robots could take pictures of secret documents and relay them to foreign agents
c. scattered nanoparticles may recombine in nature to form new elements and
chemical compounds that are highly reactive and toxic
d. waste nanomaterials may
end up in groundwater, rivers, and lakes where they kill off fish and other wildlife
NANOTECHNOLOGY WEBQUEST
Go to Nanotech Kids website: http://www.nanonet.go.jp/english/kids/indexn.html
Click on blue sphere at bottom of page - What is Nanotechnology.
1. Nano means _______________________________________________
2. nm is the unit abbreviation for __ __ __ __ __ __ __ __ __
Fill in the units
3) 1000m = _______ 5) 1/1000m = _____
4) 1/100m = ______ 6) 1/1,000,000,000m ________
28
7) According the article, what is nanotechnology?
_________________________
____________________________________________________________
____
Click on What is nanotechnology? at the bottom of the page.
Click on How small is it?
8) One nanometer = ___________-meter
9. Click on the To Smaller World button. What object is shown to be 1 nm
in size? _____
10. Click on To Larger World. What object is shown as 2,000,000 km?
__________
Click on: What is nanotechnology? at the bottom of the page.
Click on: Nanotechnology World.
11. One nanometer is about the length of __________ atoms
12.True or False Nano-sized particles of elements have the same
properties as larger
samples of the same element.
13. Describe the “TOP DOWN” method for making nano particles.
_________________
____________________________________________________________
____
14. Describe the “BOTTOM UP” method for making fine, small
things.______________
____________________________________________________________
____
15. At present these two methods of fabrication are advancing the door to
new _______
Challenge
Create a poster that will depict nanotechnology applications in society.
Student Name: ________________________________________
CATEGORY
Content Accuracy
4
3
2
1
All content
throughout the
presentation is
accurate. There
are no factual
errors.
Most of the content is
accurate but there is
one piece of
information that might
be inaccurate.
The content is
generally accurate,
but one piece of
information is
clearly flawed or
inaccurate.
Content is typically confusing or contains more
than one factual error.
29
Use of
Graphics
All graphics are
attractive (size
and colors) and
support the
theme/content of
the presentation.
A few graphics are
not attractive but all
support the
theme/content of the
presentation.
All graphics are
attractive but a few
do not seem to
support the
theme/content of
the presentation.
Several graphics are unattractive AND
detract from the content of the presentation.
Effectiveness
Project includes
all material
needed to gain a
comfortable
understanding of
the topic. It is a
highly effective
study guide.
Project includes most
material needed to
gain a comfortable
understanding of the
material but is lacking
one or two key
elements. It is an
adequate study
guide.
Project is missing
more than two key
elements. It would
make an
incomplete study
guide.
Project is lacking several key
elements and has inaccuracies
that make it a poor study guide.
Text - Font
Choice &
Formatting
Font formats (e.g.,
color, bold, italic)
have been
carefully planned
to enhance
readability and
content.
Presentation has
no misspellings or
grammatical
errors.
Font formats have
been carefully
planned to enhance
readability.
Font formatting has
been carefully
planned to
complement the
content. It may be
a little hard to read.
Font formatting makes it very
difficult to read the material.
Presentation has 1-2
misspellings, but no
grammatical errors.
Presentation has 12 grammatical
errors but no
misspellings.
Presentation has more than 2 grammatical
and/or spelling errors
Spelling and
Grammar
Resources:
1. Williams, Linda, Adams, Wade. Nanotechnology Demystified. New York: McGraw-Hill,
2007.
2. http://en.wikipedia.org/wiki/File:Schema_MEB_(en).svg*
3. http://en.wikipedia.org/wiki/File:Misc_pollen.jpg
4. http://bayblab.blogspot.com/2008/07/sem-pics.html
5. http://en.wikipedia.org/wiki/File:Ant_SEM.jpg
6. How an SEM Works: http://science.howstuffworks.com/scanning-electronmicroscope3.htm
7. Nanotechnology 101 http://nano.gov/nanotech-101
* All pictures used are under Creative Commons License. SEM images are from the Institute for
Electronics and Nanotechnology at Georgia Institute of Technology.
Vocabulary
Antibody: a blood protein produced in response to and counteracting a specific
antigen. Antibodies combine chemically with substances that the body recognizes as
alien, such as bacteria, viruses, and foreign substances in the blood.
Antigen: a toxin or other foreign substance that induces an immune response in the
body, especially the production of antibodies.
30
Biosensor: a device that uses a living organism or biological molecules, especially
enzymes or antibodies, to detect the presence of chemicals.
Vocabulary
Ohm (Ω): the SI unit of electrical resistance, expressing the resistance in a circuit
transmitting a current of one ampere when subjected to a potential difference of one
volt.
Nanopipette: nanoscale pipette used in conductance probes for scanning electron
microscope.
Electrolyte: a liquid or gel that contains ions and can be decomposed by electrolysis,
e.g., that present in a battery. Physiology: the ionized or ionizable constituents of a
living cell, blood, or other organic matter.
Nanotechnology: the branch of technology that deals with dimensions and tolerances
of less than 100 nanometers, especially the manipulation of individual atoms and
molecules.
Graphene: a fullerene consisting of bonded carbon atoms in sheet form one atom thick.
Nanotube: a tubular molecule composed of a large number of carbon atoms.
Nanotubes might replace some metal electronic components, leading to faster devices.
Nanowire: a nanoscale rod made of semiconducting material, used in miniature
transistors and some laser applications.
Associated Activities
Power of Graphene Page 3 of 14 Developed by IEEE as part of TryEngineering
www.tryengineering.org
The Power of Graphene
Teacher Resources
The "Power of Graphene" lesson explores graphene and its electrical properties and
applications at the nano scale. Students work in teams to test graphene using a
simple circuit set up and consider how this remarkable material is impacting many
31
industries. Teams evaluate their test results, develop new theoretical applications
for graphene, present their ideas to the class, and reflect on the experience.

1. Show students the student reference sheets. These may be read in class or
provided as reading material for the prior night's homework.
2. To introduce the lesson, consider asking the students what they know about
insulators and conductors and whether they think graphene would behave in either
way.
3. If internet access is available, have students review the resources at
www.trynano.org. The site will provide additional background information about
nanotechnology and the industries where it is having great impact.
4. Teams of 3-4 students will consider their challenge, and as a team theorize
whether they think graphene would conduct or insulate electric current.
5. Teams next build a working circuit using an LED light, battery, and resistor, and
then test graphene (and other materials if you would like to extend the activity) on
a piece of paper to see if it completes the circuit.
6. Teams observe what happened, compare their hypotheses to the actual results,
complete a reflection sheet, and present their experiences to the class.
Allow students to use graphite from pencil to simulate graphene paper
32
The image of graphene (Lawrence Berkley National lab)
Lesson Closure: show and tell of students’ sensors and circuits.
One of the most popular (and over used) closure techniques I have seen is
the “Exit Slip” and one that is mentioned in Teach Like a Champion. The
idea of the Exit Slip or Exit Ticket is that students need to answer a
question in order to leave the classroom. This a good way to end the
lesson, but I want to share some more ideas to help add variety to closure
activities.
1. 3-2-1 – Students write down on a note card 3 things they learned from
today’s lesson, 2 questions they have about the topic and 1 thing that they
want the teacher to know from today’s lesson.
2. Quiz – Of course a teacher can create a quick multiple choice quiz to
asses student’s understanding, BUT it’s more fun if students create their
own quiz questions. Students can quiz each other or the teacher can
compile all the quiz questions and create a quiz for the beginning of
tomorrow’s lesson.
3. Journal Entry – Have students do a quickwrite or summary of what they
learned.
4. Postcards – Have students write a post card to an absent student
explaining the key ideas presented in the day’s lesson.
5. Pair/Share – “Tell the person next to you . . .” Have students verbally
summarize main ideas, answer questions posed at the beginning of a
lesson, and link both past and future lessons.
6. Doodles – Students can sketch or draw 3 concepts they learned from the
lesson using words or images.
33
7. Gallery Walk – Students create a graphic organizer or infographic to
represent their learning. Students then post them on the wall for students
to get up and view different visual representations of understanding.
8. What’s Inside – This can be done individually, with a partner or in small
groups. Students get a sealed envelope that contains a slip of paper with a
topic, vocabulary word or problem written on it. Students then have to
explain, describe, or solve the contents of the envelope.
Source:(www.teachingfactor.wordpress.com)
Lesson Rubric: Design a rubric on how to measure forces at the
nanoscale level. Address those objectives in your rubric design:
Students will:
• Compare and contrast model probe instruments with those that are used
to make measurements of electric and magnetic forces at the nanoscale
(AFM, MEMS)
• Model how instrument probes can be used to characterize surface
interactions
• Describe how the topography of a surface relates to adhesion
• Interpret graphs of forces at the nanoscale level
• Consider the new evidence about surface topography and seta adhesive
forces to evaluate remaining methods of gecko adhesion
34
Contributors
Kester Peters, Teacher, Miami Lakes Middle School
Sponsoring Program
Research Experience for Teachers (RET) Florida International University
Engineering Center.
Acknowledgements
Program directors: Dr. Milani Masoud and Stephanie Strange.
Physics Professor and mentor: Dr. Jin He; Graduate assistant and PhD
candidate: Namuna Pandey. (Physics lab: Biosensing & Bioimaging).
References
http://www.nanonet.go.jp/english/kids/index-n.html
U.S. Science Education Standards
(http://www.nap.edu/catalog.php?record_id=4962)
• U.S. Next Generation Science Standards (http://www.nextgenscience.org/)
• International Technology Education Association's Standards for
Technological Literacy (http://www.iteea.org/TAA/PDFs/xstnd.pdf)
• U.S. National Council of Teachers of Mathematics' Principles and Standards
for School Mathematics
(http://www.nctm.org/standards/content.aspx?id=16909)
• U.S. Common Core State Standards for Mathematics
(http://www.corestandards.org/Math)
• Computer Science Teachers Association K-12 Computer Science Standards
(http://csta.acm.org/Curriculum/sub/K12Standards.html)
P.B. Tiwari;L. Astudillo;J. Miksovska;X. Wang;W. Li;Y. Darici;J. He,
Nanoscale 6 (2014) 10255-63
www.tryengineering.org
35
Karayiannakis, Anastasios J. et al. "Circulating VEGF Levels in the Serum
of Gastric Cancer Patients." Annals of Surgery 236.1 (July 2002): 37-42.
Web. 4 Mar 2010. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1422546/
Prof. Dr. Kenji Yasuda & Hyoncho Kim from Department of Biomedical
Information, Tokyo Medical and Dental University.
Nader Pourmand's lab, Nanopipette Group. UCSC Baskin Engineering.
Senkei Umehara, Post Doc in Nader Pourmand's lab, Nanopipette Group.
UCSC Basking Engineering
"Thermo Scientific: Pierce Protein Research." Sulfo-SMCC
(Sulfosuccinimidyl 4- N-maleimidomethyl]cyclohexane-1-carboxylate). Web.
3 Mar 2010.
http://www.piercenet.com/products/browse.cfm?fldID=02030378.
"Thermo Scientific: Pierce Protein Research." EDC (1-Ethyl-3-[3dimethylaminopropyl]carbodiimide Hydrochloride) . Web. 3 Mar 2010.
http://www.piercenet.com/Objects/View.cfm?type=ProductFamily&ID=0203
0312.
36
37