Laser sniffs out toxic gases from afar. Duke Today, December 3, 2014. Scientists have developed a way to sniff out tiny amounts of toxic gases — a whiff of nerve gas, for example, or a hint of a chemical spill — from up to one kilometer away. The new technology can discriminate one type of gas from another with greater specificity than most remote sensors — even in complex mixtures of similar chemicals — and under normal atmospheric pressure, something that wasn’t thought possible before. Picked up by NPR affiliate WUNC.