Multifunctional Fe3O4 cluster@ quantum dot-embedded mesoporous SiO2 nanoplatform probe for cancer cell fluorescence-labelling detection and photothermal therapy

Abstract

Composite nanomaterials have recently amassed increasing interests in biomedical applications because of the limited function of pure material. This work designed a uniform and multifunctional nanoplatform (NPF) probe composed of superparamagnetic ferroferric oxide (Fe3O4) cluster as core and mesoporous silica embedded with CdTeS quantum dots (QDs) as middle layer wrapped by the outer silica shell. The Fe3O4 cluster core served as the magnetic and photothermal agent, and the CdTeS QDs served as the fluorescence-labelling agent. For the first time, quantities of QDs were embedded into the mesoporous silica based on electrostatic interaction and physical absorption, which are superior to the traditional crosslink-loading method. The NPF probes were successfully internalized into cancer cell with the decoration of folic acid. Transmission electron microscopy (TEM), X-ray diffraction (XRD), vibrating sample magnetometry (VSM), fluorescence spectrophotometer, and temperature detector were used to detect the NPF probe. The NPF probe was verified to possess excellent magnetic, fluorescent, and photothermal properties suitable for multiple medical applications. More importantly, a collaborative diagnosis–treatment probe that combines fluorescence labelling and photothermal therapy exhibited the perfect behaviour of labelling and destroying cancer cells in vitro.