Direct sunlight enabled photo-biochemical synthesis of silver nanoparticles and their Bactericidal Efficacy: Photon energy as key for size and distribution control
Direct sunlight enabled photo-biochemical synthesis of silver nanoparticles and their Bactericidal Efficacy: Photon energy as key for size and distribution control
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DOI：
10.1016/j.jphotobiol.2018.08.019
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发表时间：
2018-11-01
影响因子：
5.4
通讯作者：
Gopal, Ram
中科院分区：
文献类型：
--
作者：
Bhardwaj, Abhishek Kumar;Shukla, Abhishek;Gopal, Ram
非常需要发现新颖的绿色合成方法来廉价且可规模化地合成纳米颗粒（NP），以减少对环境的负面影响。但这些方法通常在控制纳米颗粒产品的尺寸、形状和同质性方面提出了巨大的挑战。在本研究中，我们报告了一种利用直射阳光和平菇（Pleurotus citrinopileatus）提取物进行银纳米颗粒光生化合成的新方法。使用不同波长的阳光来控制光生化产生的纳米颗粒的尺寸和分布。有趣的是，据观察，较短波长的太阳光产生较小尺寸且尺寸分布较窄的纳米颗粒。例如；蓝色阳光产生的胶体银纳米颗粒的平均直径类似于 3.28 nm 和 0.72 nm 的尺寸分布，而全阳光产生的胶体银纳米颗粒的尺寸相对较大（7.08 nm），且具有更宽的尺寸分布（2.92 nm）。由于本方法仅使用直射阳光、可免费获得的可再生能源、廉价的生物提取物作为还原剂和封端剂以及廉价的银前体，因此它是一种环境友好的方法，可用于工业规模的纳米颗粒合成。此外，还研究了针对致病性大肠杆菌的尺寸依赖性杀菌效果。对于平均直径为 3.28 nm 的银纳米颗粒，观察到的最低抑制浓度 (MIC) 为 25 ppm，MBC 为 30 ppm。
It is highly desirable to discover novel green synthesis methods for cheap and scalable synthesis of nanoparticles (NPs) to reduce the negative impact on the environment. But these approaches generally impose great challenge in controlling size, shape, and homogeneity of product NPs. Here in the present study, we report a novel approach enabling direct sunlight and oyster mushroom (Pleurotus citrinopileatus) extract for the photo-biochemical synthesis of Ag NPs. Sunlight of different wavelength was used to control the size and distribution of photo biochemically produced NPs. Interestingly, it is observed that a smaller wavelength of sunlight produces smaller sized of NPs with a narrow size distribution. For examples; blue sunlight produces colloidal silver NPs with an average diameter of similar to 3.28 nm and 0.72 nm size distribution, while full sunlight produces comparatively larger sized (7.08 nm) NPs with wider (2.92 nm) size distribution. Since present approach uses only direct sunlight, freely available renewable energy source, a cheap biological extract as reducing and capping agent and cheap silver precursor, therefore it is an environment-friendly approach and can be used for the synthesis of NPs at industrial scale. Moreover, the size-dependent bactericidal effect has also been studied against pathogenic, Escherichia colt, bacteria. The minimum inhibitory concentration (MIC) 25 ppm and MBC 30 ppm have been observed for silver NPs of 3.28 nm average diameter.