A hollow Cu9S8 theranostic nanoplatform based on a combination of increased active sites and photothermal performance in enhanced chemodynamic therapy

•Hollow structure was used to increase the active sites for chemodynamic therapy.•Hollow Cu9S8 nanoparticles exhibit better chemodynamic performance than solid one.•Combination of increased active sites and photothermal effect to enhance therapy.•Hollow Cu9S8 is a low cost “all in one” nanoplatform for theranostics. A theranostic nanoplatform, combined with tumor imaging and therapy, especially a highly reactive multimodal synergistic treatment, can effectively improve the efficacy of treatment and reduce costs. Copper sulfide can be used as a theranostic nanoplatform due to its strong photoacoustic, photothermal, and Fenton-like catalytic performance. However, its Fenton-like catalytic performance is limited by the availability of surface reaction sites. A hollow Cu9S8 theranostic nanoplatform, with photoacoustic imaging and enhanced chemodynamic performance based on the combination of an increased number of active sites and photothermal performance was constructed in this study. The specific area of the hollow Cu9S8 nanoparticles was 1.7 times greater than that of solid Cu9S8 nanoparticle, which greatly increased the number of active sites where catalysis could occur in the Fenton reaction, thereby improving the chemodynamic therapy performance. In addition, the excellent photothermal properties of the Cu9S8 nanoparticles accelerated the generation of hydroxyl radicals (OH), which also enhanced the chemodynamic therapy performance. More importantly, the in vivo experiment demonstrated that the hollow Cu9S8 theranostic nanoplatform exhibit good tumor photoacoustic imaging and enhanced chemodynamic therapy due to the combination of the increase in number of active sites and photothermal performance. Therefore, this work not only provides an excellent theranostic nanoplatform for tumor treatment, but also a new strategy for developing high performance chemodynamic agents.