1. Nanotechnology for Energy
Fuel Cell Applications
Nanoparticles show promise as a fuel cell membrane material that will improve the performance and efficiency of the cell.
The membrane in the middle may be made of nanoparticles to improve the performance of the fuel cell.

2. Nanoparticles in Medicine
In medicine, nanoparticles are being used to
Detect and diagnosis diseases in their very early stages. For example, breast cancer can currently only be detected after more than a million cancer cells are present. Scientists are trying to develop nanotechnologies that can detect this cancer at an earlier stage, when only 100 to 1000 cells have grown. Another example is the use of nanoparticles to diagnosis Alzheimer's earlier than is now possible.
Regenerate damaged cells that do not normally reproduce, e.g., in the nervous system. Nanoparticles are being designed that may spur the reproduction of these cells to allow recovery from spinal cord or brain injuries.
Repair or destroy diseased cells without harming healthy ones. This would lower the risk of side-effects from chemotherapy, for example. Currently, one of the greatest challenges to cancer treatment is to selectively destroy or prevent the replication of cancer cells while leaving healthy cells untouched. Nanoparticles are being used to help target cancer cells.
In this illustration, biological molecules related to DNA are attached to gold nanoparticles. The resulting species can be used as drugs to seek out and prevent diseased cells from reproducing.
Reference: David A. Giljohann; Dwight S. Seferos; Andrew E. Prigodich; Pinal C. Patel; Chad A. Mirkin; J. Am. Chem. Soc.  2009, 131,
DNA-like molecules can be attached to gold nanoparticles. The resulting nanoparticle complex is designed to seek out and repair or destroy diseased cells such as cancer cells.

3. Nanoparticles in Medicine: Drug Delivery
Cisplatin is an effective cancer treatment drug containing a platinum atom in each molecule. The figure above shows how one research group attached cisplatin to nanoparticles to improve the targeted delivery of the drug to cancer cells.
Reference: Shanta Dhar; Weston L. Daniel; David A. Giljohann; Chad A. Mirkin; Stephen J. Lippard; J. Am. Chem. Soc.  2009, 131,
The effective cancer treatment drug cisplatin can be attached to nanoparticles for delivery to cancer cells.

4. Nanoparticles in Medicine: Cancer Therapy by Hyperthermia
Among the researchers world-wide investigating medical uses for nanoparticle materials, NIST scientists have recently made breakthroughs in understanding the magnetic behavior of iron oxide (magnetite) particles. This work may assist in the medical use of such particles for treatment of cancer by hyperthermia whereby cancer cells are overheated and destroyed by nanoparticles. The heat is generated by a magnetic field outside the patient interacting with the magnetic nanoparticles, causing them to warm.
In the image here, a 9 nm wide magnetite (iron oxide) nanoparticle with a shell (green) and core (magenta). The magnetic fields (indicated by the small black arrows) of the core and shell line up with or at right angles to the external field (blue arrow).
This work also has implications for the use of such nanoparticles in data storage devices.
Reference:

5. Gold Nanoparticles in Medicine: Cancer Diagnosis and Treatment
Imaging
X-ray contrast agent (high-Z materials)
Therapy
X-ray dose enhancement (high-Z materials)
Photothermal ablation
Gamma- and beta-radiation therapy
Focusing on gold nanoparticles for cancer diagnosis (imaging) and cancer treatment (therapy):
A gold atom is relatively heavy: because it has 79 protons and 118 neutrons, it is in the top third of the periodic table in terms of atomic mass. This means that it also has many electrons (79 in a neutral atom to balance the protons’ positive charges), and these electrons interact with light waves, such as X-rays. The more electrons, the greater the absorption and emission of X-rays. Thus, gold nanoparticles serve as excellent “high Z materials” (where Z is the number of protons or electrons in a neutral atom).
High Z materials are used to image the cells in which they accumulate by using X-rays which are absorbed in greater amounts by the materials than by “lighter” surrounding tissue. We call such high Z materials “X-ray contrast agents” because they provide light and dark contrast between high Z and low Z materials in X-ray images. The same phenomenon is responsible for typical X-ray images in which you can see bones through skin and organs. Bones are denser than the surrounding soft tissues, such as skin, muscle, and most organs, and therefore absorb more X-rays.
If gold nanoparticles are directed to cancer cells, they allow these cells to be detected in X-ray images by absorbing the X-rays and appearing dark in X-ray images.
The same effect can destroy cancer cells as well: high Z materials not only absorb but also re-emit these X-rays into the surrounding tissues. If the high Z materials are near tumors, the tumors are exposed to greater doses of X-rays and thereby killed. This effect is called “dose enhancement.”
Similarly, gold nanoparticles may absorb infrared (IR) radiation and heat up. The effect is the same as for hyperthermia described in the previous slide, except that here, IR radiation is used to heat the nanoparticles rather than magnetic fields. Nearby tumor cells are overheated and die.
Finally, gold nanoparticles may be made radioactive. The radiation emitted by them may strike nearby tumor cells, killing these cells.

6. Environmental Applications: Nitrate and Nitrite Detection
Here, nanoparticles are used to measure the level of the nitrite ion (nitrate-sensitive nanoparticles have also been made) in water supplies. The Maximum Contamination Level (MCL) is 21.7 micromoles per liter as highlighted in red. Nitrate and nitrite have been linked to a number of medical complications, including some reproductive problems, and so their levels in water supplies are regulated.
In the example above, the color of the nanoparticle solution is directly related to the concentration of dissolved nitrite. The test is designed for the identification of nitrite levels above the MCL using the naked eye.
Reference: Weston L. Daniel; Min Su Han; Jae-Seung Lee; Chad A. Mirkin; J. Am. Chem. Soc.  2009, 131,
Nanoparticles can be used to measure the concentration of toxins in water. Here, the amount of nitrite is related to the color of the nanoparticle solution.

7. Research Project Topics for Students
Environmental fate of nanoparticles: Where do they end up after we use them?
Biological effects: Are any nanoparticles toxic? If so, how are they harmful?
The future of nanoparticles: What new exciting devices or applications will nanoparticles be used for in the future?
More topics can be found using the links given on the following slide.
Students are also encouraged to look into the topics presented on earlier slides, such as the uses of nanoparticles in energy, medicine, and a variety of consumer products.

8. Online Resources for Learning About Nanoscience
National Technology Initiative
Nanoscience Education Resources, New Mexico State University, Alamogordo
National Science Foundation
Discover Nano, Northwestern University
Rice University
The Project on Emerging Nanotechnologies
These links will also take you to numerous other sites with resources for teaching and learning about nanoscience.

9. Experiments and Activities to teach Nanoscience
1. How small are nano-sized objects? How can they be measured?
Scale and Measurement module, Measurement of diameter of a hair
Measurement of a thin film of oleic acid
Cutting it down to nano activity (can you cut a piece of paper into nanoscale sized pieces?)
Nanosugar (based on idea that 1 sugar molecule = 1 nm):
2. How do properties of nanomaterials differ from bulk materials?
See slides “Size Matters”

10. a) Differences in optical properties –see Size matters slide 6
See Making Gold Nanoparticles Lab
b) Increased surface area (increased no. of nucleation sites): Alka seltzer, cards/blocks: Size Matters activities
Picture of blowing light powder (flour?) over a lighter
Could also heat nail and then steel wool in Bunsen burner flame
Increased surface area with a tofu block
Another example: mentos in coke
c) Diffusion rates: Nanodiffusion – see gelatin diffusion experiment

11. Acknowledgments
This presentation contains data and contributions from scientists at the National Institute of Standards and Technology:
Dr. Ashley Beasley Green
Dr. Russell Watson
Chemical Sciences Division
Chemical Sciences Division (now at Nalco)
Dr. Debbie Kaiser
Material Measurement Laboratory
Dr. Gale Holmes
Materials Science and Engineering Division
Dr. Thomas LeBrun
Mechanical Metrology Division

13. Nanomeasurements and Nanoproperties: Exploring Nanoscience
Mary Satterfield