Novel N-TiO2/SiO2/Fe3O4 nanocomposite as a photosensitizer with magnetism and visible light responsiveness for photodynamic inactivation of HeLa cells in vitro

Semiconductor photocatalyst materials based on TiO 2 are potential photosensitizers for photodynamic therapy of cancer. Despite its effectiveness under ultraviolet light, pure TiO 2 shows almost no photocatalytic activity under visible light because of its wide intrinsic band gap energy (anatase, 3.2 eV). Besides, TiO 2 has no magnetic delivery property. In this study, an inorganic nanocomposite, N-TiO 2 /SiO 2 /Fe 3 O 4 , is successfully prepared in three steps by means of co-precipitation, Stöber and sol-gel methods. Deep characterization results by XRD , TEM, XPS , UV–vis DRS, FL and magnetic hysteresis loop reveal that N-TiO 2 /SiO 2 /Fe 3 O 4 has core-shell structure, magnetic property and visible-light-response capability. As a potential photosensitizer for photodynamic therapy, it shows a stronger photodynamic suppression effect on proliferation of HeLa cells than TiO 2 under the irradiation of xenon light.