Effectiveness of different accelerated green synthesis methods in zinc oxide nanoparticles using red pepper extract: Synthesis and characterization

Abstract

Potential ability of red pepper extract in zinc oxide nanoparticles (ZnO NPs) fabrication via three accelerated heating techniques, namely, conventional heating with stirring (at 100°C and 700 rpm, for 30 min), autoclave (at 15 psi and 121°C, for 15 min), and microwave irradiation (power of 800 W for 3 min) was assessed. Fourier transform infrared spectroscopy and gas chromatography mass spectroscopy indicated that the prepared extract contained 20 active compounds including alcohols, aldehydes, ketones, esters, and organic acids with several functional groups such as hydroxyls. Results indicated that ZnO NPs with spherical and hexagonal structures have been formed using three different heating methods, and the minimum crystal size for the fabricated ZnO NPs was 88.44 nm, which was attained using heating by autoclave. Antioxidant activity of the synthesized ZnO NPs was determined using the red pepper extract, and accuracy of this method was 80.21%. Finally, results indicated that the formed ZnO NPs had high antibacterial activity against Staphylococcus aureus, Escherichia coli, and Enterococcus faecalis and high antifungal activity against Aspergillus niger and Aspergillus flavus.

Keywords

• accelerated heating method
• antimicrobial activity
• green synthesis
• red pepper extract
• zinc oxide nanoparticles