Silver nanoparticles Synthesis by coffee residues extract and their antibacterial activity

Objective(s): Nowadays, nanotechnology is growing rapidly due to its high application in science and industry. Particularly in recent years, the synthesis of green nanoparticles has been of great interest with plant extracts. It is a simple, inexpensive and environmentally friendly method. The possibility of synthesizing nanoparticles from vegetable wastes has been investigated in this article. Methods: coffee powder was used to produce nanoparticles. Silver ions were found to decrease with coffee extract and resulted in the formation of silver nanoparticles crystals. The properties of nanoparticles synthesized by coffee powder were analyzed by various methods such as UV spectroscopy, scanning electron microscopy (SEM) and X-ray diffraction. In addition, antibacterial activity of synthesized nanoparticles against two bacteria Escherichia coli and Pseudomonas aeruginosa was done by paper disk and optical absorption method. Results: The formation of silver nanoparticles was confirmed (by the presence of an absorption peak at 460 nm) using a spectrophotometer. The images of the electron microscope showed that the nanoparticles were spherical and had an average size about 50 nm. The X-ray diffraction has clearly proven the field of silver nanoparticles. The results of microbial tests also indicated that the synthesized nanoparticles had an appropriate effect on the two tested bacteria Conclusions: This experiment showed that coffee residues extracts can be used for green synthesis of nanoparticles, which also have an appropriate antibacterial effect.