Microwave synthesis of copper oxide nanoparticles using tea leaf and coffee powder extracts and its antibacterial activity

Abstract

Oxides of copper have been investigated for decades due to their unique semiconductor and optical properties. The review of literature revealed that very few reports are available on the synthesis of copper oxide nanoparticles using microorganisms and plant extracts. In this paper, we have reported the synthesis of copper oxide nanoparticles (CuO) using tea leaf and coffee powder extracts under microwave irradiations. The synthesis was carried out by irradiating metal salt and the extracts of tea and coffee in 1:3 ratio in a microwave at 540 W for 7-8 min. The synthesized nanoparticles were characterized by Scanning electron microscope, X-ray diffraction, UVvisible spectroscopy and Fourier transform infrared spectroscopy. The antibacterial activity of these nanoparticles was tested against six human pathogenic microbes. It was interesting to find that these nanoparticles possess remarkable antibacterial activity against two human pathogenic bacteria. Moreover, the use of environmentally benign materials for the synthesis of CuO nanoparticles offers numerous benefits of eco-friendliness and compatibility for pharmaceutical and other biomedical applications.

Preparation and characterization of ascorbic acid-mediated chitosan–copper oxide nanocomposite for anti-microbial, sporicidal and biofilm-inhibitory activity

“…Ascorbic acid may act as a reducing and stabilizing agent for the formation of CuO nanocomposites. Similar to our report, Sutradhar et al [15] visualized color change of copper oxide nanoparticles from light orange to brownish-black color when adding coffee powder extract to copper salt.…”

Biofabrication of copper oxide nanoparticles using Andean blackberry (Rubus glaucus Benth.) fruit and leaf

“…The UV-visible spectra did not change even after a prolonged storage. The spectra clearly agree with the result enlightens that the synthesized nanoparticles were found to be symmetrical, with spherical in nature [16][17]24 ]. …”

“…are given much attention. In literature, biofabrication of CuO-NPs using magnolia leaf/plant extract [14], yeast, and fungi [15], algae [16], tea leaf and coffee powder [17] has been already reported.…”

Properties and characterization of agar/CuNP bionanocomposite films prepared with different copper salts and reducing agents

“…The absorption spectra of CuA AA , CuC AA , and CuS AA nanoparticles showed peaks at 250-270 nm, whereas, in the respective CuNPs/agar BNC films the absorption peaks were broader and shifted to 240 nm. Sutradhar et al (2014) reported the absorption peaks of CuO nanoparticles at 271 and 269 nm synthesized by tea and coffee extract, respectively.…”