Friday, August 14, 2009

Researchers at MIT have for the first time shown that carbon nanotubes can grow without a metal catalyst. The researchers demonstrate that zirconium oxide, the same compound found in cubic zirconia "fake diamonds," can also grow nanotubes, but without the unwanted side effects of metal. Another advance on fabricating carbon nanomaterials has been reported by a Northwestern University professor and his students, who have found a new way of turning graphite oxide – a low-cost insulator made by oxidizing graphite powder – into graphene, a hotly studied material that conducts electricity. In this flash reduction process, researchers simply hold a consumer camera flash over the graphite oxide and, a flash later, the material is now a piece of fluffy graphene.

If man-made devices could be combined with biological machines, laptops and other electronic devices could get a boost in operating efficiency. Lawrence Livermore National Laboratory researchers have devised a versatile hybrid platform that uses lipid-coated nanowires to build prototype bionanoelectronic devices.

nanobioelectronic device

An artist's representation of a nanobioelectronic device incorporating alamethycin biological pore. In the core of the device is a silicon nanowire (grey), covered with a lipid bilayer (blue). The bilayer incorporates bundles of alamethicin molecules (purple) that form pore channels in the membrane. Transport of protons though these pore channels changes the current through the nanowire. (Image: Scott Dougherty, LLNL)

When bees sting, they pump poison into their victims. Now the toxin in bee venom has been harnessed to kill tumor cells by researchers at Washington University School of Medicine in St. Louis. The researchers attached the major component of bee venom to nano-sized spheres that they call nanobees.

In other news in cancer-fighting nanomedicine, researchers at Wake Forest University have increased the tumor-killing power of carbon nanotubes by encasing them in DNA. The DNA-encasement of the tubes actually increased the amount of heat produced upon irradiation of the nanotubes with near-infrared light and appears to be a promising new tool for hyperthermia applications.

Growing – and precisely aligning – spear-shaped zinc oxide crystals with a diameter of 100-200 nm on a surface of single-crystal silicon, researchers at Missouri University of Science and Technology may have developed a method to make more efficient solar cells. By growing zinc oxide on top of the silicon, you're putting two semiconductors on top of each other, thereby widening the spectrum from which a solar cell could draw light.