In this illustration, a “smart rust” nanoparticle attracts and traps estrogen molecules, which are represented by the floating objects. Credit: Dr. Dustin Vivod and Prof. Dr. Dirk Zahn, Computer Chemistry Center (CCC), Friedrich-Alexander-Universität Erlangen-Nürnberg Pouring flecks of rust into water usually makes it dirtier. But researchers have developed special iron oxide nanoparticles they call “smart
