Size-controlled synthesis of fluorescent tungsten oxide quantum dots via one-pot ethanol-thermal strategy for ferric ions detection and bioimaging

As one typical semiconductor material, tungsten oxide (WO3) has captivated intensive attention owing to its multifunctional properties. However, exploring a facile and one-pot strategy for controllable synthesis of fluorescent tungsten oxide quantum dots (WO3 QDs) is still very challenging. In this paper, WO3 QDs were prepared via a facile and one-pot ethanol-thermal approach in the presence of H2O2, and the growth mechanism was investigated in detail. Encouragingly, as evidenced by the transmission electron microscope and the atomic force microscope, the average size and topographic height of WO3 QDs were adjusted ranging from 23.5 to 2.3 nm and 21.3 to 2.2 nm via ethanol-thermal treatment with different amount of H2O2. The as-prepared WO3 QDs exhibited excellent water-solubility, highly fluorescence stability, low toxicity and good biocompatibility, resulting in their successful applications in specific ferric ions detection and bioimaging in vitro. Furthermore, this significant strategy would pave the way for the controllable fabrication of other transition metal oxides.