Wadhwani Sweety A, Shedbalkar Utkarsha U, Singh Richa, Karve Meena S, Chopade Balu A
Department of Microbiology, University of Pune, Pune, 411007, Maharashtra, India,
World J Microbiol Biotechnol. 2014 Oct;30(10):2723-31. doi: 10.1007/s11274-014-1696-y. Epub 2014 Jul 1.
Gold nanoparticles have enormous applications in cancer treatment, drug delivery and nanobiosensor due to their biocompatibility. Biological route of synthesis of metal nanoparticles are cost effective and eco-friendly. Acinetobacter sp. SW 30 isolated from activated sewage sludge produced cell bound as well as intracellular gold nanoparticles when challenged with HAuCl4 salt solution. We first time report the optimization of various physiological parameters such as age of culture, cell density and physicochemical parameters viz HAuCl4 concentration, temperature and pH which influence the synthesis of gold nanoparticles. Gold nanoparticles thus produced were characterized by various analytical techniques viz. UV-Visible spectroscopy, X-ray diffraction, cyclic voltammetry, transmission electron microscopy, selected area electron diffraction, high resolution transmission electron microscopy, environmental scanning electron microscopy, energy dispersive X-ray spectroscopy, atomic force microscopy and dynamic light scattering. Polyhedral gold nanoparticles of size 20 ± 10 nm were synthesized by 24 h grown culture of cell density 2.4 × 10(9) cfu/ml at 50 °C and pH 9 in 0.5 mM HAuCl4. It was found that most of the gold nanoparticles were released into solution from bacterial cell surface of Acinetobacter sp. at pH 9 and 50 °C.
由于具有生物相容性，金纳米颗粒在癌症治疗、药物递送和纳米生物传感器方面有广泛应用。金属纳米颗粒的生物合成途径具有成本效益且环保。从活性污水污泥中分离出的不动杆菌属SW 30，在受到HAuCl4盐溶液挑战时会产生细胞结合型以及细胞内的金纳米颗粒。我们首次报道了对各种生理参数（如培养物的年龄、细胞密度）和物理化学参数（即HAuCl4浓度、温度和pH值）的优化，这些参数会影响金纳米颗粒的合成。如此产生的金纳米颗粒通过各种分析技术进行了表征，即紫外可见光谱、X射线衍射、循环伏安法、透射电子显微镜、选区电子衍射、高分辨率透射电子显微镜、环境扫描电子显微镜、能量色散X射线光谱、原子力显微镜和动态光散射。在50°C和pH值为9的条件下，在0.5 mM HAuCl4中，通过细胞密度为2.4×10(9) cfu/ml的24小时培养物合成了尺寸为20±10 nm的多面体金纳米颗粒。结果发现，在pH值为9和50°C时，大多数金纳米颗粒从不动杆菌属的细菌细胞表面释放到溶液中。
