Materials Science Division, Poornaprajna Institute of Scientific Research, Bidalur, Near Devanahalli, 562110 Bengaluru, Karnataka, India; Manipal Academy of Higher Education (MAHE), Manipal 576104, India.
Department of Applied Physics, Indian Institute of Technology (Indian School of Mines), Dhanbad 826004, India.
Mater Sci Eng C Mater Biol Appl. 2020 Jan;106:110182. doi: 10.1016/j.msec.2019.110182. Epub 2019 Sep 10.
This study highlights the investigation of the green fluorescence in NaTb(WO) materials (NaTbW Bulk and NaTbW Nano) synthesized via template free hydrothermal method as a function of particle size and morphology. Herein, we demonstrated the biocompatibility and intracellular green fluorescence of NaTbW Nano samples using HeLa cells for cell imaging applications. Powder X-ray diffraction studies showed that the as synthesized NaTbW Bulk and NaTbW Nano crystallize in the Scheelite like tetragonal crystal system with the I4/a space group. The reaction pH and solvent is observed to play a critical role in determining particle size, shape and morphology of these luminescent materials. Furthermore, size dependent optical properties were systematically studied by diffuse reflectance, steady state photoluminescence; time resolved fluorescence lifetime and quantum yield measurements. Both the materials have shown bright green fluorescence upon UV excitation as a function of particle size. Remarkable high quantum yield of NaTbW Bulk indicated its greater luminescence efficiency and the closer CIE coordinates to the commercial green illuminant suggested their potential use in solid state display systems. On the other hand the observed biocompatibility of NaTbW Nano particles towards mammalian cancer HeLa cells, Staphylococcus aureus, Escherichia coli and the intracellular green fluorescence rightly proved its functionality as active bio-probes. Thus, our work summarize the potential use of these Scheelite like NaTb(WO) material for solid state display and bio-imaging applications.
本研究重点研究了无模板水热法合成的 NaTb(WO)材料（NaTbW 体相和 NaTbW 纳米）的绿色荧光，作为粒径和形貌的函数。本文通过 HeLa 细胞的细胞成像应用，展示了 NaTbW 纳米样品的生物相容性和细胞内绿色荧光。粉末 X 射线衍射研究表明，所合成的 NaTbW 体相和 NaTbW 纳米在 Scheelite 型四方晶系中结晶，具有 I4/a 空间群。反应 pH 值和溶剂对这些发光材料的粒径、形状和形貌起着关键作用。此外，通过漫反射、稳态荧光、时间分辨荧光寿命和量子产率测量系统地研究了尺寸依赖性光学性质。这两种材料在紫外光激发下均表现出明亮的绿色荧光，这与粒径有关。NaTbW 体相具有显著的高量子产率，表明其具有更高的发光效率，并且 CIE 坐标更接近商用绿光照明，这表明它们可能用于固态显示系统。另一方面，NaTbW 纳米颗粒对哺乳动物癌细胞 HeLa、金黄色葡萄球菌、大肠杆菌的生物相容性观察，以及细胞内绿色荧光的观察，证明了其作为活性生物探针的功能。因此，我们的工作总结了这些 Scheelite 型 NaTb(WO)材料在固态显示和生物成像应用中的潜在用途。
