In recent years, synthesis of nanoparticles using vegetal extract has gained much interest in nanobiotechnology. The aim of this study is the biosynthesis of silver nanoparticles (AgNPs) from silver nitrate using spruce (Picea abies L.) bark as a bioresource of cost-effective nonhazardous reducing and stabilizing compounds. The effects of various parameters such as concentration of reactants, ratio extract/silver nitrate and time of incubation on the controlled formation of AgNPs were explored. The AgNPs were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, ultraviolet-visible-near infrared spectroscopy and scanning electron microscopy. A stock solution of silver nitrate (0.1 M) was prepared. Different concentrations of silver nitrate (1, 2.5, 4, and 5 mM) were prepared from the above solution, then added to 5 mL of spruce bark extract. The synthesis of AgNPs was confirmed by the change in the color of the mixtures from brown to grey. It was noticed that the synthesized nanoparticles have sizes between 0.1 and 0.5 µm (100–500 nm) with an average diameter of 0.226 µm (226 nm). The antibacterial activity of synthesized AgNPs was investigated in vitro. It was found that the most potent antibacterial activity appeared in AgNPs compared to the aqueous extract or silver nitrate.

中文翻译：

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云杉云杉皮水提液生物合成银纳米颗粒及其抗菌活性

近年来，使用植物提取物合成纳米颗粒已引起人们对纳米生物技术的极大兴趣。这项研究的目的是使用云杉（Picea abies）从硝酸银生物合成银纳米颗粒（AgNPs）。L.）树皮作为具有成本效益的无害还原和稳定化合物的生物资源。探索了反应物浓度，提取物/硝酸银比例和孵育时间等各种参数对AgNPs受控形成的影响。通过X射线衍射，傅立叶变换红外光谱，紫外-可见-近红外光谱和扫描电子显微镜对AgNPs进行表征。制备硝酸银的储备溶液（0.1M）。从上述溶液中制备不同浓度的硝酸银（1、2.5、4和5 mM），然后将其加入5 mL云杉树皮提取物中。通过从棕色到灰色的混合物的颜色变化证实了AgNP的合成。注意到合成的纳米颗粒的尺寸在0.1和0之间。5 µm（100–500 nm），平均直径为0.226 µm（226 nm）。体外研究了合成AgNPs的抗菌活性。发现与水提取物或硝酸银相比，AgNPs表现出最强的抗菌活性。