Multifunctional PVP-Ba2GdF7:Yb3+, Ho3+ coated on Ag nanospheres for bioimaging and tumor photothermal therapy

Photothermal therapy (PTT) guided by bioimaging has attracted much attention. Recently, the multifunctional nanomaterials with multimodal imaging and high-performance therapy effect are extremely important. In this work, a novel nanostructure with Ag nanospheres (NSs) encapsulated Polyvinylpyrrolidone (PVP) film which decorated by Ba2GdF7:Yb3+, Ho3+ nanoparticles is synthesized by a simple method. The novel nanostructure endows the NCs remarkable originality and excellent multifunctional performance. The morphology, structure, optical properties, biocompatibility, cytotoxicity, superparamagnetic properties and photothermal therapeutic efficiency of the [email protected]2GdF7:Yb3+, Ho3+ nanocomposites (NCs) are investigated. The results show that [email protected]2GdF7:Yb3+, Ho3+ NCs possess good upconversion luminescence (UCL) performance and X-ray computed tomography (CT) imaging ability. Furthermore, in MTT cytotoxicity measurement, the NCs exhibit low cytotoxicity and excellent biocompatibility. Moreover, the PVP film coating of the NCs can largely promote the stability. In addition, outstanding photothermal conversion ability and stability are also obtained upon NIR laser irradiation. Utilizing the prominent photothermal effect, PTT in vitro shows efficient photothermal killing effect on tumor cells. Therefore, [email protected]2GdF7:Yb3+, Ho3+ NCs from multifaceted research provides a break to multifunctional nanomaterials for multimodal imaging detection and high-performance tumor photothermal therapy.