A dipstick test has been developed by University of Illinois researchers which can be deployed for detecting cocaine and other banned substances in urine, blood or saliva. The test has been created on the basis of DNA-gold nanoparticle technology. These colorimetric sensors are based on lateral flow separation of aptamer-linked nanostructures. As per Yi Lu, Chemistry professor, University of Illinois: The new sensors offer a quick and convenient test that can be utilized by first responders or emergency room staff to quickly screen individuals for a variety of drugs and other chemicals. The team created highly sensitive and selective colorimetric sensors which are similar to litmus paper tests and you can get to read more about the research in Angewandte Chemie International Edition journal.