Fe(III)-coordination-driven fabrication of self-supplying oxygen and charge-convertible nanoplatform for enhanced photodynamic therapy of tumor

•A self-supplying oxygen and charge-convertible nanoplatform were designed and fabricated via coordination-induced self-assemblies of polymer ligand.•Obtained nanoplatforms exhibited excellent stability and high drug loading capacity.•This nanoplatform can enhance cellular uptake and activated PDT by gradient pH changes.•This nanoplatform endows the self-oxygenation-boosted ROS generation ability.•This nanoplatform shows good cancer cell killing efficiency and biocompatibility.