Abstract

Due to the biocompatibility and eco-friendly properties of silver nanoparticles (AgNPs), their aqueous synthesis is gaining great attention. Herein, we report the biosynthesis of AgNPs using Ginkgo biloba (G. biloba) leaf aqueous extract without using toxic chemicals. The synthesis conditions have been investigated by the factorial design of experiments (FDE) by exploring reaction conditions such as concentration ratio, media pH, reaction temperature as well as duration. The results demonstrate that the heating of 0.5 mL of as-prepared G. biloba leaf extract and 5.0 mL of 0.5 mM AgNO₃ at 80 °C for 30 min in a mild alkaline medium (pH 9) were the optimal reaction parameters. The uniform spherical shapes AgNPs with particle size 14.14 ± 4.44 nm was confirmed by the techniques such as scanning electron microscope (SEM), high-resolution transmission electron microscope (HRTEM), energy dispersive X-ray (EDX) spectroscopy, selected area electron diffraction (SEAD) pattern and dynamic light scattering (DLS). It is clearly observed that the as-synthesized AgNPs are efficiently hindered the growth of both gram-positive and negative bacteria. Furthermore, they also showed ten times faster degradation of azo-dyes according to the pseudo-first-order kinetics and its constant (k). In addition, they demonstrated an efficient fluorescent probe for hexavalent chromium detection. The green synthesis of such environment-friendly AgNPs in bulk shows that this method has potential industrial application prospects.

Graphic Abstract

中文翻译：

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银杏叶水提液合成银纳米粒子的生物学和环境应用

摘要

由于银纳米颗粒（AgNPs）的生物相容性和环保特性，其水合成受到了广泛的关注。在此，我们报道了使用银杏叶（G. biloba）叶水提取物而不使用有毒化学物质进行AgNPs的生物合成。通过探索性实验设计（FDE），通过研究反应条件，例如浓度比，介质pH，反应温度以及持续时间，研究了合成条件。结果表明加热了0.5 mL制备的银杏叶提取物和5.0 mL的0.5 mM AgNO ₃在中性碱性介质（pH 9）中于80°C放置30分钟是最佳反应参数。通过扫描电子显微镜（SEM），高分辨率透射电子显微镜（HRTEM），能量色散X射线（EDX）光谱，选择区域电子衍射等技术确认了粒径为14.14±4.44 nm的均匀球形AgNPs （SEAD）模式和动态光散射（DLS）。清楚地观察到，合成后的AgNP有效地阻碍了革兰氏阳性和阴性细菌的生长。此外，根据拟一级动力学及其常数（k），它们还显示出偶氮染料的降解速度快十倍。此外，他们展示了一种用于六价铬检测的高效荧光探针。

图形摘要