(Frontiers) The bizarre optical properties of tiny metal particles — smaller than light waves — can be captured on paper to detect even a single target molecule in a test sample. These hyper-sensitive testing devices could be assembled and customized at the point of use in low-resource environments, with virtually limitless applications spanning medicine, forensics, manufacturing and environmental safety.

Original source: https://www.eurekalert.org/pub_releases/2019-03/f-qpa032519.php