Self‐Templated Stepwise Synthesis of Monodispersed Nanoscale Metalated Covalent Organic Polymers for In Vivo Bioimaging and Photothermal Therapy

Size‐ and shape‐controlled growth of nanoscale microporous organic polymers (MOPs) is a big challenge scientists are confronted with; meanwhile, rendering these materials for in vivo biomedical applications is still scarce. In this study, a monodispersed nanometalated covalent organic polymer (MCOP, M=Fe, Gd) with sizes around 120 nm was prepared by a self‐templated two‐step solution‐phase synthesis method. The metal ions (Fe 3+ , Gd 3+ ) played important roles in generating a small particle size and in the functionalization of the products during the reaction with p ‐phenylenediamine (Pa). The resultant Fe‐Pa complex was used as a template for the subsequent formation of MCOP following the Schiff base reaction with 1,3,5‐triformylphloroglucinol (Tp). A high tumor suppression efficiency for this Pa‐based COP is reported for the first time. This study demonstrates the potential use of MCOP as a photothermal agent for photothermal therapy (PTT) and also provides an alternative route to fabricate nano‐sized MCOPs.