Fast Colorimetric Sensing of Adenosine and Cocaine Based on a General Sensor Design Involving Aptamers and Nanoparticles

Apt to change color: DNA aptamers have been used to assemble DNA-functionalized gold nanoparticles to produce highly sensitive and selective colorimetric sensors with an instantaneous color response on addition of a substrate. The general method has been shown for adenosine and cocaine (see picture), but should be applicable to any aptamer of choice.