Spotlighting nanotech research at Purdue

• Cancer detection: Ultra-sensitive medical imaging of cells for cancer detection could be possible with tiny "nanorods" made of gold. By injecting the rods into the bloodstream of mice and shining a laser through the skin, Purdue researchers found the nanorods yielded images nearly 60 times brighter than the conventional fluorescent dyes commonly used for biological imaging used to study the inner workings of cells and molecules. The gold rods are roughly 200 times smaller than a red blood cell.

• Nanomeasurements: Fitting together nanodevices will likely require ultra-precise measurement of their tiny components, and researchers might use still tinier hollow fibers called "multi-walled carbon nanotubes" to make such measurements. Because these nanotubes are relatively long and slender, they can penetrate the nooks and crannies of nanostructures, and Purdue engineers are learning to use them as probes attached to the tips of atomic force microscopes. Engineers also have led research aimed at overcoming the van der Waals forces that often cause nanotubes to stick to structures. New findings could lead to more accurate measurements using the slender probes.

• Hydrogen batteries: Hydrogen fuel cells could automatically recharge batteries in portable electronics products such as notebook computers, eliminating the need for a wall outlet, if metal nanoparticles prove as useful as Purdue research suggests. Tiny particles of aluminum only about 100 nanometers wide are a key component in hydrogen-releasing pellets that could be contained in credit-card-sized cartridges. Once the pellets are used up, a new cartridge would be inserted into devices such as cell phones, personal digital assistants, notebook computers, digital cameras, handheld medical diagnostic devices and defibrillators. The method also might have military applications in portable electronics for soldiers and for equipment in spacecraft and submarines.

• Nano-optics: Better telecommunications technologies as well as a "superlens" that could dramatically improve the quality of medical diagnostic imaging might be possible with a radical new material made of nanorods. The material has a property unheard of in nature, called a "negative index of refraction," which could make it possible to take optical images of objects that are smaller than the wavelength of visible light, including molecules such as DNA, for research and medical imaging. Purdue scientists also said this effect, impossible to achieve with lenses made of materials with positive refractive indices, occurs at the wavelength of light used for telecommunications, which could lead to better communications and imaging technologies.

• Molecular electronics: Electronic devices based on DNA molecules are the goal of Purdue engineers, who have attached magnetic "nanoparticles" to DNA and then cut these "DNA wires" into pieces, offering the promise of creating low-cost, self-assembling devices for future computers. By placing positively charged magnetic particles into a solution with the negatively charged DNA, the attraction between them allows the DNA to act as tiny scaffolds for creating wires. This sort of self-assembly might be used in the future to create electronic devices at lower cost than is possible with conventional manufacturing processes.

• Nanotherapy: Custom therapies to fight cancer and viruses could be created from nanoparticles made of RNA, a chemical cousin to DNA. A Purdue team has shown that RNA shows promise as a functionally flexible material and is exploring ways to use the RNA both as the scaffolding that provides structure to the nanoparticles and as the therapeutic agent the particles deliver to the body. With further research, the nanoparticles could deliver a wide variety of custom-designed therapeutic RNA strands directly to infected cells.

Biochips: Screening food for toxins could be possible with "biochips," or miniature electronic sensors capable of rapidly detecting biological entities from air or water, that Purdue engineers are developing. The sensors incorporate natural proteins with electronic chips to rapidly detect a variety of toxins, including substances that might be used by terrorists, in food, water or the air. This technology will likely be used in food processing and inspection operations to screen for pathogens and ensure the safety of our food supply. Engineers say it could be ready for commercial production within a few years.

Writers: Emil Venere, (765) 494-4709, venere@purdue.edu

Chad Boutin, (765) 494-2081, cboutin@purdue.edu

Purdue News Service: (765) 494-2096; purduenews@purdue.edu

Related release:
Purdue's Discovery Lecture Series focuses on nanotechnology

To the News Service home page