Nanoparticles are an attractive means for molecular imaging and targeted delivery of therapeutics. In article number adtp.201800133 Jianxiang Zhang, Karlheinz Peter and co-workers synthesize and characterize the functionality of a self-assembled, ROS-responsive fluorescent nanoprobe. Using in vivo mouse studies, the authors demonstrate the feasibility and great potential of these nanoparticles as a tool for diagnostic and therapeutic targeting of cardiac tissue undergoing ischemia/reperfusion injury.