Nanosensors might also sniff out cancer earlier and with more precision than current tests. High sensitivity means only a small blood sample is needed -- comparable to the fingerprick used by diabetics to monitor glucose levels. Such a test could be invaluable for people with a family history of disease, for example, either to quickly identify the need for treatment or to set their minds at ease that they are healthy. The tests themselves might be inexpensive and so easy to use that they could be bought over the counter at a drugstore. We reported on the work of Charles Lieber at Harvard and James Heath, a physical chemist at the California Institute of Technology, developing such sensors.

Nanoscale particles could also be used as a core delivery device for the detection, imaging, and targeted and personalized treatment of cancer. This has the potential of transforming cancer treatment, killing more tumors, while at the same time eliminating the usual side effects of chemotherapy or radiation therapy. James Baker, a physician and professor at the University of Michigan, has developed a delivery system that could make it into human trials next year.

Universal Memory
While self-assembly might one day transform computer manufacturing, more near-term applications are likely to come from hybrid solutions that combine new nanoparticles and existing fabrication techniques. This path is being followed by Nantero, a company that has created a process for making so-called universal memory. This type of computer memory could store information without a continuous source of power, similar to the flash card in a digital camera, yet access it very quickly, like the memory inside a PC. Nantero's technique incorporates nanotubes into traditional semiconductor fabrication processes. The company says partners using the nanotube technology will make announcements about actual products in 2006.

Nano and the Environment
Nanotechnology is leaping technical hurdles -- but ultimately its success will depend on winning over consumers. And that will mean assuring the public that nano-scale materials are safe. The very aspects that make nanotechnology so exciting -- novel properties emerging at this scale and the ability to subtly and precisely modify these properties, with such dramatic results -- raise questions about how these new substances will behave in the environment, including the human body. This year there have been growing efforts to discover the environmental and health effects of nanomaterials. Now many nanotech proponents say that the coming year will be a critical window of opportunity for demonstrating that researchers and industry take safety concerns seriously. It will be a time to find and deal with any existing problems -- before they become dire-sounding headlines. However, whether 2006 will also bring the increased organization, cooperation, and funding needed to make this oversight happen remains an open question.