The tool, developed by Australian doctoral research student David Beale is based on chemiluminescence -- a highly-sensitive technique that reveals the presence of minute quantities of an organic compound.
http://ummid.com/news/2011/December/17.12.2011/tool_to_detect_pesticide.htm
http://ummid.com/news/2011/December/17.12.2011/tool_to_detect_pesticide.htm