A Finer Gauge of Distance

by Philip Ball Nature Materials Update, 31 Mar 2005 A 'ruler' for measuring distances of just 1-3 nm has been developed by researchers at Harvard University. They show that the fluorescent light emission from an organic dye molecule can be switched off by red light, but that the close proximity of another dye switches the fluorescence back on. The effect depends very sensitively on the distance between them. Read the article