A CAMERA that takes four hours to take a picture and only works in red light doesn鈥檛 sound like a whole lot of use on the face of it.
But the 鈥渓iving camera鈥�, which records high-resolution images on a film of light-sensitive bacteria, could allow nano-materials to be produced with unprecedented precision.
The camera, developed by Chris Voigt and colleagues at the University of California, San Francisco, uses light to switch on genes in genetically modified bacteria, which in turn produce a dark chemical that records the image. Because the bacteria are so small, the sensor has a resolution of 100 megapixels per square inch (Nature, vol 438, p 441).
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To make their novel biosensor, Voigt鈥檚 team implanted genes from photosynthesising cyanobacteria into the cell membranes of E. coli bacteria. One gene was for a red light sensor, and the other was a gene that is switched on when the sensor is activated, producing a black chemical. When the team exposed a dense bed of the modified bugs to an image lit with red light for four hours, they found they could produce a permanent monochrome print on the 鈥渇ilm鈥�.
Their success could lead to the development of nano-factories in which light is used to 鈥減rint鈥� substances in precise amounts and at specific locations on a surface, such as polymer-like proteins or even metals. 鈥淭he bacteria could weave a complex material,鈥� says Voigt. Nobel prizewinning nanotechnologist Harry Kroto says this type of chemical modification is an 鈥渆xtremely exciting advance鈥�.
