Nano scale biological imaging

This article on biologynews.net features news about nano scale cantilevers. The term cantilever is usually used in engineering to refer to a structure in which there are overhanging beams. Using cantilevers on a scale small enough to insert into biological cells, nanotechnicians can design each microscopic beam to attract some substances and not others. The increased weight on each beam created by attracting specific substances changes the frequency of a laser beam bounced off it. Using these nano devices and precision lasers, it is possible to detect the presence or absence of substances within an individual cells and parts of cells and to build images on a microscopic scale. According to the article:

...scientists with the Molecular Foundry, a U.S. Department of Energy User Facility located at Berkeley Lab, have developed nano-sized cantilevers whose gentle touch could help discern the workings of living cells and other soft materials in their natural, liquid environment. Used in combination with a revolutionary detection mechanism, this new imaging tool is sensitive enough to investigate soft materials without the limitations present in other cantilevers. [...]
Rather than measuring the cantilever's deflection by bouncing a laser off it, Ashby and Sanii place the nanowire cantilever in the focus of a laser beam and detect the resulting light pattern, pinpointing the nanowire's position with high resolution. The duo say this work provides a launching pad for building a nanowire-based atomic force microscopes that could be used to study biological cells and model cellular components such as vesicles or bilayers. In particular, Ashby and Sanii hope to learn more about integrins, proteins found on the surface of cells that mediate adhesion and are part of signaling pathways linked to cell growth and migration.

An accessible basic description of their use in cancer research can be found at nano.cancer.gov.