4 research outputs found

    Bacteria-Mediated Ultrathin Bi<sub>2</sub>Se<sub>3</sub> Nanosheets Fabrication and Their Application in Photothermal Cancer Therapy

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    Bismuth selenide (Bi<sub>2</sub>Se<sub>3</sub>) attracts a lot of attention nowadays due to its unique electronic and thermoelectric properties. In this study, fabrication of Bi<sub>2</sub>Se<sub>3</sub> nanosheets by selenite-reducing bacterium (SeRB) was first reported. Morphology, size, and location of the biogenic Bi<sub>2</sub>Se<sub>3</sub> are bacteria-dependent. It is difficult to separate Bi<sub>2</sub>Se<sub>3</sub> generated by <i>Bacillus cereus</i> CC-1 (Bi<sub>2</sub>Se<sub>3</sub>-C) from the biomass because of strong interaction with the cell membrane. However, Bi<sub>2</sub>Se<sub>3</sub> produced by <i>Lysinibacillus</i> sp. ZYM-1 (Bi<sub>2</sub>Se<sub>3</sub>-Z), is highly dispersed in extracellular space with high stability. Further characterization by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM) on Bi<sub>2</sub>Se<sub>3</sub>-Z indicates that the product is a rhombohedral-phase, ultrathin nanosheet-like structure with an average size of ∼100 nm. Subsequently, the photothermal performance of Bi<sub>2</sub>Se<sub>3</sub>-Z with the irradiation of 808 nm near-infrared (NIR) laser was determined. When the Bi<sub>2</sub>Se<sub>3</sub>-Z concentration was 26 mg L<sup>–1</sup>, and irradiation power was 2 W, the photothermal conversion efficiency was calculated as 30.7%. At the same condition, 100% of the MCF7 and A549 cancer cells were killed within 10 min of irradiation in vitro. Moreover, using 1% (v/v) PVP as surfactant, a novel nanodumbbell structure of Bi<sub>2</sub>Se<sub>3</sub> was obtained. Overall, this bacteria-driven Bi<sub>2</sub>Se<sub>3</sub> fabrication paves a new way for biocompatible photothermal nanomaterials

    GRID: a student project to monitor the transient gamma-ray sky in the multi-messenger astronomy era

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