Antimony-Doped Tin Oxide Nanocrystals for Enhanced Photothermal Theragnosis Therapy of Cancers

The doped semiconductor nanocrystal with free holes in valence band exhibits strong near-infrared (NIR) local surface plasmon resonance effects, which is essential for photothermal agents. Herein, the hydrophilic Sb doped SnO(2) nanocrystals were successfully prepared by a simple hydrothermal synthesis method. The doping makes the Sb doped SnO(2) nanocrystals possessing defect structures. Compared with the un-doped SnO(2) nanocrystals, Sb doped SnO(2) nanocrystals exhibit stronger absorption in the NIR region from 500 to 1,100 nm and higher photothermal conversion efficiency (up to 73.6%) which makes the synthesized Sb doped SnO(2) nanocrystals be used as excellent photothermal agents. Importantly, Sb doped SnO(2) nanocrystals can efficiently kill cancer cells both in vitro and in vivo under the irradiation of a 980 nm laser with a power density of 0.6 W cm(–2). In addition, Sb doped SnO(2) nanocrystals can also be served as efficient CT imaging agents owing to the large X-ray attenuation coefficient of tin.