Biological and Environmental Applications of Silver Nanoparticles Synthesized Using the Aqueous Extract of Ginkgo biloba Leaf

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.