Gold Nanoparticles from Vegetable Extracts Using Different Plants from the Market: A Study on Stability, Shape and Toxicity

Abstract

The use of nanoparticles for many advanced applications (drug‐delivery, biosensors, catalysts etc.) involves their large scale production. This engenders the need of synthetic methods and reactants which are sustainable as well as safe. Natural products allow to prepare nanoparticles via eco‐friendly processes, which is especially true for reducing/capping agents obtained from agricultural by‐products. Here, we prepared gold nanoparticles (AuNPs) in high yields by using extracts from the leaves of marketable plants and by following different synthetic routes (i. e. one‐ or two‐steps). The size and morphology of the obtained AuNPs were determined by Transmission Electron Microscopy (TEM), while surface coverage with different chemical species was investigated by surface‐enhanced Raman scattering (SERS). In vitro experiments on bone‐marrow mesenchymal stromal cells (MSCs) were used to study the effect on cell viability, as a first step toward toxicity assessment. This work allowed to select the nanoparticles with highest SERS activity at infrared excitation wavelength, in view of their possible use as shelf products.

Sono-Biosynthesis and Characterization of AuNPs from Danube Delta Nymphaea alba Root Extracts and Their Biological Properties

“…Although the experimental conditions used in the biosynthesis of the nanoparticles did not translate into marked differences in the pattern of the XRD diffractograms, slight shifts in the diffraction peak positions were observed, reflecting the differences found in the dimensions of the gold core. They presented an average core size lower than 20 nm (AuNPR4 < AuNPR3 ≈ AuNPR2 < AuNPR5 ≈ AuNPR1), which is in good agreement with results from other nanoparticles synthesized with plant extracts [73][74][75][76][77][78][79][80], although it seems to be independent of the root extract concentration. The observed core size of the AuNPRn is much smaller than the respective measured hydrodynamic size, which is due to the fact that the hydrodynamic diameter also reproduces the presence of the coating of biomolecules from the root extracts around the nanoparticle core, whereas the crystallite diameter is restricted to its core diameter.…”

Role of polyphenols in plant-mediated synthesis of gold nanoparticles: identification of active components and their functional mechanism

“…The experimental results indicate that 0.04-0.08 mg ml −1 may be an appropriate polyphenols concentration and have a certain guiding significance for the actual preparation of GNPs. (2) The results of GNPs preparation from different plant resources are different [49,50], which may be due to the differences in the polyphenols content of different plants. The suitable plant resource can be screened out in accordance with the optimal polyphenols concentration.…”

Rapid SERS Detection of Thiol-Containing Natural Products in Culturing Complex

“…Especially, thiols are known to interact covalently with noble metal surfaces [ 37 – 39 ], establishing a sulfur-metal bond that has been also exploited for producing self-assembled monolayers on gold nanocavities, which would generally provide escalated SERS signals indicating the information of chemical structure. With natural products involved, multiple implementations have been performed in SERS-based analysis including the study of molecular configurations [ 40 ], molecular screening over herbal or plant extracts [ 41 – 43 ], quality control for natural product based medicines [ 44 ], and archaeological examination for artificial textiles [ 45 ].…”