Hollow capsules made of an organic conducting polymer could act as “roach motels” for bacteria. The microbes, which have an overall negative electrical charge, can get stuck on thin sheets or filaments extruding from the positively charged traps. When exposed to light, the capsules produce a very reactive form of oxygen highly toxic to bacteria—after one hour they killed more than 95 percent of nearby germs. The particles, built by scientists at the University of Florida and the University of New Mexico, can be applied to various surfaces, including medical equipment. The findings were presented online November 24 by ACS Applied Materials & Interfaces.