A general sol–gel process has been developed to form a coating of resorcinol–formaldehyde (RF) resin on inorganic nanostructures of various compositions and morphologies. The RF shell can be conveniently converted into carbon through high temperature carbonization under an inert atmosphere.

Synergistic cancer starvation/ROS-mediated/chemo-therapy is developed through a cascade reaction with enzyme glucose oxidase (GOX) modified on the surface of an Fe-based metal organic framework (MOF(Fe)) and drug camptothecin (CPT) loaded into the cavities of MOF(Fe). Once internalized by tumor cells, GOX catalyzes endogenous glucose into hydrogen peroxide (H₂O₂) and gluconic acid (H⁺) enabling starvation therapy through choking off energy (glucose) supply. Meanwhile, the acidic micro-environment of tumor enhanced by the generated H⁺ degrades the MOF(Fe) simultaneously releasing CPT for chemotherapy and Fe³⁺, catalyzing H₂O₂ into one of the strongest reactive oxygen species (ROS) ˙OH enabling ROS-mediated therapy. Both in vitro and in vivo results show remarkable tri-modal synergistic anticancer effects. This work may shed some light on the development of novel multi-modal cancer therapies without any external intervention.