Gold and silver nanoparticles are utilized in various industrial applications because of their unique properties. Physical, chemical, and green methods exist to synthesize these plasmonic nanoparticles. In green synthesis, biocompatible compounds, plants or their extracts, and microorganisms such as yeast, bacteria, actinobacteria, fungi, and algae are used to synthesize gold and silver nanoparticles. These biological sources have biomolecules that produce plasmonic gold and silver nanoparticles by reducing gold and silver ions. Green synthesis is easy, secure, high-yield, economically sensible, and eco-friendly. The synthesized nanoparticles should be characterized to determine their physiochemical properties (size, shape, surface, homogeneity, stability, and other properties). There are various techniques for the characterization of plasmonic nanoparticles, such as transmission electron microscopy, ultraviolet-visible spectroscopy, Fourier transform infrared, dynamic light scattering, and zeta potential. Gold and silver nanoparticles have diverse applications including antimicrobial and antitumor activities, usage in textile, food, and agriculture industries, wastewater treatment, and bioremediation. This review paper aims to introduce gold and silver nanoparticles and their synthesis approaches with an emphasis on green synthesis, explain different characterization techniques, and express the applications of these nanoparticles in biotechnology. |
