Ecofriendly synthesis of silver and gold nanoparticles by Euphrasia officinalis leaf extract and its biomedical applications

Abstract

Biogenic synthesis of silver (AgNPs) and gold nanoparticles (AuNPs) using aqueous extract of Euphrasia officinalis has been reported. Stable AgNPs and AuNPs were formed on adding aqueous solutions of silver nitrate and chloroauric acid with E. officinalis leaf extract, in 19 min and 2 min, respectively. The synthesis method used in present study was simple, reliable, rapid, cost effective and ecofriendly. The synthesized nanoparticles were characterized with field emission transmission electron microscopy (FE-TEM), elemental mapping, selected area diffraction pattern (SAED), energy-dispersive X-ray spectroscopy (EDS), X-ray diffractometer (XRD), particle size distribution, zeta potential and Fourier-transform infrared spectroscopy (FTIR). The UV-Vis spectrum confirmed the synthesis of nanoparticles as the absorption band was observed at 450 nm for AgNPs and at 558 nm for AuNPs. The TEM images revealed quasi-spherical shape of AgNPs and AuNPs. The size of nanoparticles was determined to be 40.37 ± 1.8 nm for AgNPs and 49.72 ± 1.2 nm for AuNPs. The zeta potential value demonstrated the negative surface charge and stable nature of nanoparticles. Crystalline nature of the nanoparticles in the face-centred cubic (fcc) structure was confirmed by the peaks in the XRD pattern and SAED pattern. FTIR results showed the functional groups involved in reduction of silver and gold ions to metal nanoparticles. For biomedical application, the nanoparticles have been explored for anticancer, antibacterial and biofilm inhibition activities. It was observed that AgNPs exert anticancer activity against human lung cancer (A549) and human cervical cancer (HeLa) cell lines. On the other hand, AuNPs were able to inhibit only human cervical cancer cells. Furthermore, the AgNPs were active against clinically isolated human pathogens like Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus and Vibrio parahaemolyticus. Additionally, AgNPs also showed biofilm inhibition activity against S. aureus and P. aeruginosa.

Silver‐gold alloy nanoparticles biofabricated by fungal xylanases exhibited potent biomedical and catalytic activities

“…These features rise from the combined oscillation of free conduction electrons persuaded by an interrelating magnetic field. Au and Ag nanoparticles are exceptional nanomaterials that provide a great platform in the biomedical uses of biomolecular recognition, drug delivery, biosensing, and molecular imaging . When related with monometallic nanoparticles, bimetallic nanoparticles have worthy catalytic properties due to the synergetic effects between two metals …”

“…Au and Ag nanoparticles are exceptional nanomaterials that provide a great platform in the biomedical uses of biomolecular recognition, drug delivery, biosensing, and molecular imaging. [50][51][52][53] When related with monometallic nanoparticles, bimetallic nanoparticles have worthy catalytic properties due to the synergetic effects between two metals. 44,54,55 Authors have described the use of certain higher plants, such as the leaves of Swietenia mahogani, Jasminum sambac, Anacardium occidentale, Commelina nudiflora, and fruit peel of Lansium domesticum 45,48,[56][57][58][59] for the green synthesis of Ag-AuNPs.…”

Characterization, antibacterial, total antioxidant, scavenging, reducing power and ion chelating activities of green synthesized silver, copper and titanium dioxide nanoparticles using Artemisia haussknechtii leaf extract

“…For example, using a various chemicals as precursors and more amounts of surfactants as stabilizing agents is one of the common methods in NPs synthesis. In this way, there are the different preparation methods in the synthesis of metallic NPs from several materials [4]. Today, the way of NP synthesis with a small size is important part of nanotechnology function [5].…”

Microwave-assisted green synthesis and antimicrobial activity of silver nanoparticles derived from a supercritical carbon dioxide extract of the fresh aerial parts of <i>Phyllanthus niruri</i> L

“…This is the fast and easy way of green synthesis. The lower energy consumption, shorter reaction time and improved yields are the advantages of the microwave assisted synthesis of AgNPs [5,6,7].…”