LEFT: A strong permanent magnet is able to concentrate the iron oxide materials (nMAG) much as is observed in hexanes. RIGHT: the fluorescence of quantum dots (QD) is relatively unchanged after the formation of a bilayer and the transfer of the materialinto water.
Nanomaterials are tiny particles with unique magnetic, optical and chemical properties that could be useful in a variety of socially-beneficial applications such as water purification and medical imaging. In order for nanomaterials to work in the body or in contaminated water they have to be dispersible in water. Current methods for making some of the most promising materials—iron oxide and cadmium selenide nanoparticles—involve the use of oily solvents, which limits the particles’ application in water-based systems. A new technique allows the particles to be transferred from the oily solvents in which they are synthesized into water-based solutions while still retaining the attractive properties. Using a trick borrowed from the way detergents surround oil and dirt on laundry in the washing machine, the oily particles are mixed with water containing a small concentration of oleic acid, which is a long molecule that has a water-compatible end and an oil-compatible end. When just the right amount of fatty acid is present, a bilayer forms around the nanoparticle, shielding it from the water and allowing it to remain stable. Using this technique, 70% of nanoparticles were transferred from their oily solvent into water. Follow-up experiments showed that the nanoparticles retained their unique optical and magnetic properties in their new watery environment.
Application of antiHER2 targeted nanoshells creates a red hue in tumor tissue that can be visualized macroscopically (above) and microscopically (below), using near-infrared reflectance confocal microscopy.
Researchers in the Center for Biological and Environmental Nanotechnology have come up with a way to make tiny particles into beacons for identifying cancer cells during breast cancer surgery. Accurate determination of the edges of a breast cancer tumor during surgery is one of the most important factors in preventing the cancer’s recurrence. Current techniques rely on the surgeon’s assessment during the surgery followed up by post-operative examination of the tissue samples. Some patients have access to specialized facilities that can examine the cells under a microscope while the patient is still on the operating table but this is a lengthy procedure and is unavailable at many community hosptials. Nanoshells, which are tiny particles of silica with a gold coating, could allow surgeons to get an answer in the operating room within five minutes, thereby reducing both cancer recurrence and the length of time the patient must be sedated. Professor Rebekah Drezek and colleagues tag the nanoshells with a marker that links them to a type of cancer cells known as HER and then light them up using near-infrared light in a technique known as reflectance confocal imaging. These results were published in the journal Breast Cancer Research and Treatment.
Nanomagnetite removes arsenic.
CBEN scientists have signed an agreement with the University of Guanajuato and the Municipal Water and Sewerage Authority of Guanajuato (Simapag) to pilot test the use of nanotechnology to clean contaminated water in Guanajuato, Mexico. The agreement is the first known test of nanoparticles for water treatment in a municipal water treatment plant. The groundwater that Guanajuato uses as a partial source for drinking water contains arsenic, and this test bed will explore the possibility of using a nanomagnetite-packed column for the removal of arsenic either during or after sand filtration. Nanomagnetite is also known as “nano-rust” due to its small particle size and iron oxide chemical composition. Laboratory tests have demonstrated that nano-rust is very effective at removing arsenic from water. A second study is being conducted to determine if C60 and titanium dioxide nanoparticles can improve the efficiency of ultraviolet-light based disinfection systems which could permit the use of more energy-efficient light-emitting diodes as the excitation source. In March 2010, the team of researchers recently completed a nine-day field test of both the nanomagnetite and UV-disinfection systems at the SIMAPAG municipal water treatment plant in Guanajuato. Jade Boyd, Rice’s associate director for news and media relations, accompanied the team and set up a blog to document their experiences: http://guanajuato.blogs.rice.edu/. The blog makes fascinating reading as it details the highs and lows of real-world fieldwork. The Canadian Broadcasting Company was on site to film the experiments for its long-running science program, “The Nature of Things,” and will be featuring the work in an hour-long episode on nanotechnology scheduled to air in early 2011. A video of the field test can be accessed at http://www.youtube.com/watch?v=wKcE__MmzFY.
Teachers in Houston, TX (foreground) and in Boulder, Colorado (background) participating in CHEM 570.
To expand the reach and impact of our professional development program, CBEN staff and faculty experimented with videoconferencing and live online classes in both our CHEM 570 Nanotechnology for Teachers spring semester course and in a fall workshop. Using distance technology, Hutchinson and Nichol expanded the enrollment in the course from 27 teachers in 2008 to 50 teachers in 2009. The spring course met for 14 consecutive weeks with each class consisting of a nanotechnology research presentation by a graduate student originating from Rice, a discussion of curriculum implementation originating either at Rice or at ATLAS, and a discussion of chemistry pedagogy originating from ATLAS. In the fall of 2009, we invited our 2008 and 2009 CHEM 570 participants to attend a videoconferenced workshop where we connected four sites: a suburban Houston high school (Langham Creek High School, Cypress Fairbanks School District), a diverse community college (San Jacinto, Pasadena, TX), a large public university (University of Colorado), and a small private university (Rice University). This workshop consisted of 16 teachers who shared how they had integrated the course content into their classrooms. In addition, Nichol provided an update on several of the research projects that the teachers had learned about in class and Hutchinson lead an interactive dialogue about strengthening students’ concepts in chemistry.
A high school teacher learns about Atomic Force Microscopy
In 2010, Drs. Colvin, Hutchinson and Nichol were awarded an NSF Research Experience for Teachers (RET) grant for $203,234 (EEC-0908968) that will build upon our CHEM 570 course, provide teachers with summer research internships and expanded teacher workshops. This RET has an emphasis on sharing information to teachers and students about career opportunities in science and engineering. In addition, Drs. Hutchinson and Nichol successfully leveraged the support from CBEN and a 2008 Texas Space Grant Consortium and were awarded a National Science Foundation grant entitled "REU Site: Nanotechnology Research Experiences with a Focus on Community Colleges," for $234,434 (EEC-0852008) starting September 1, 2009 and ending August 31, 2012. These awards will allow us to continue our successful Nanotechnology programs beyond CBEN’s sunset.
Nanomaterials represent an exciting new area of materials science that will make important contributions to every sector of the economy, including improving energy efficiency, advancing medical diagnosis and therapy and cleaning up the environment. But some of these novel particles have been shown to be hazardous, and current government guidance indicates that caution when handling them in the laboratory or factory is prudent. Now there is a resource that can help researchers and workers get the information they need to handle nanomaterials safely. In June 2009, the International Council on Nanotechnology, an outreach effort of the National Science Foundation-funded Center for Biological and Environmental Nanotechnology, announced the creation of the GoodNanoGuide, an online repository of information and practical guidance for safe handling of nanomaterials. Created in a wiki format, the GoodNanoGuide allows registered users to create and edit content with the latest information and guidance from around the world. Features include an occupational health and safety reference manual, an expert matrix of practices for specific tasks and the GoodNanoGuide Forum which provides a collaborative space for people to post and discuss items and news of interest to the community.
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