美国科学60秒 SSS 2013-08-05（在线收听）

 　　It's similiar to a pregnancy test: a drop of liquid on a strip of paper causes an easily seen color change. But imagine that kind of simple, cheap technology employed in testing for pollution or health issues anywhere and on the cheap. Researchers at Colorado State University describe such a system in the journal Lab on a Chip. Other paper tests may give only slight color differences and some relies on expensive equipment to read their results. For the new technology, the research team designed a system that creats a dramatic color change on the paper. The user drops liquid to be analyzed at the bottom of the paper. As capillary action pulls the liquid up, substances in the paper react causing the color change. So far, three tests exist for the system. One looks for nickle which can be an environmental pollutant. The other two are for glutathione, a health marker, and glocose for diabetics. In trials,the paper tests competed with conventional methods at measuring concentrations. The university is now spinning off a company to develop the technology. If successful, it could bring cheap, easy analysis to scientists and citizens around the world.