The biomedical applications of nanotechnology have attracted much attention in recent years.One of them is using nanoparticles as drug delivery systems for on-demand release of therapeutic agents.While the medication doses may be oversized in conventional pharmaceutical therapies,nanoparticle systems with high loading efficiency,targeted delivery and controlled release of drugs could greatly enhance the therapeutic effect.Among the various external stimuli,near-infrared(NIR)light was considered to be an effective tool in photothermal therapy.One irreplaceable advantage is its deep penetration but minimal absorbance of normal tissues1.Copper sulfide,as a well-known p-type semiconductor material,recently emerged as the new photothermal ablation(PTA)agents in photothermal therapy.CuS nanoparticles have various advantages such as low cost,low cytotoxicity and the intrinsic NIR absorption derived from energy band transitions instead of surface plasmon resonance.In this study,we designed a smart photothermally controllable drug delivery system based on mesoporous silica nanoparticles(MSN)and copper sulfide nanospheres.MSNs are ideal drug delivery platforms for loading drugs,due to their biocompatibility,mesoporous structures,large surface areas,and tunable pore sizes and volumes2.The oligonucleotide-modified mesoporous silica was loaded with doxorubicin(DOX),and then hybridized with copper sulfide with a complementary DNA sequence.In this design,CuS nanoparticles played the roles as both capping,and photoablation agents.When irradiated by NIR laser,the localized heat generated would make the DNA duplex dehybridized and DOX was released.The synergistic effect from NIR-triggered DOX release and photothermal ablation would be a promising approach in treatment of cancer cells,especially for the drug-resistant ones.