Room‐Temperature‐Phosphorescence‐Based Dissolved Oxygen Detection by Core‐Shell Polymer Nanoparticles Containing Metal‐Free Organic Phosphors

Abstract The highly sensitive optical detection of oxygen including dissolved oxygen (DO) is of great interest in various applications. We devised a novel room‐temperature‐phosphorescence (RTP)‐based oxygen detection platform by constructing core–shell nanoparticles with water‐soluble polymethyloxazoline shells and oxygen‐permeable polystyrene cores crosslinked with metal‐free purely organic phosphors. The resulting nanoparticles show a very high sensitivity for DO with a limit of detection (LOD) of 60 n m and can be readily used for oxygen quantification in aqueous environments as well as the gaseous phase.