Background: Herein, we report the biosynthesis procedure to prepare silver nanoparticles as reduction and capping agents with the aqueous plant extract of Perovskia abrotanoides.

Methods: The therapeutic application of silver nanoparticles entirely depends on the size and shape of the nanoparticles therefore, their control during the synthesis procedure is so important. The effects of synthesis factors, for example, silver ion concentration, the mass of plant extract, reaction time and extraction temperature, on the size of silver particles were considered and optimized. Several analytical methods were used for the characterization of silver NPs including FT-IR and UV–Vis spectrophotometer, XRD and SEM.

Results: The results showed that the mean size of the silver particles was about 51 nm. Moreover, the antibacterial properties of biosynthesized silver NPs were investigated by the minimum inhibitory concentration, minimum bactericidal concentration, and Well-diffusion tests. The minimum inhibitory concentration/ minimum bactericidal concentration values of silver NPs and aqueous plant extract versus Gram-positive bacteria (Staphylococcus aureus and Bacillus cereus) and Gram-negative bacteria (E. coli) were 3.03/0.00, 1.20/0.01, 3.06/0.00, 0.98/1.04, 1.00/0.05 and 1.30/0.03 (mg/mL), respectively.

Conclusion: The antimicrobial activity study displayed that the synthesized silver nanoparticles by plant extract have better antimicrobial properties compared to aqueous plant extract of Perovskia abrotanoides.

背景：在此，我们报道了生物合成程序，该工艺制备了银纳米颗粒，作为还原剂和加帽剂，与Perovskia abrotanoides的水性植物提取物一起使用。

方法：银纳米颗粒的治疗应用完全取决于纳米颗粒的大小和形状，因此，在合成过程中对其进行控制非常重要。考虑并优化了合成因素，例如银离子浓度，植物提取物的质量，反应时间和提取温度对银颗粒尺寸的影响。几种分析方法用于表征银纳米颗粒，包括FT-IR和UV-Vis分光光度计，XRD和SEM。

结果：结果表明，银颗粒的平均尺寸为约51nm。此外，通过最小抑菌浓度，最小杀菌浓度和良好扩散试验研究了生物合成的银纳米颗粒的抗菌性能。银NP和水生植物提取物相对于革兰氏阳性菌（金黄色葡萄球菌和蜡状芽孢杆菌）和革兰氏阴性菌（大肠杆菌）的最小抑菌浓度/最小杀菌浓度值为3.03 / 0.00、1.20 / 0.01、3.06 / 0.00 ，0.98 / 1.04、1.00 / 0.05和1.30 / 0.03（mg / mL）。

结论：抗菌活性研究表明，植物提取物合成的银纳米颗粒与水合Perovskia abrotanoides的水性植物提取物相比具有更好的抗菌性能。