Microwave-Assisted Green Synthesis of Silver Nanoparticles Using Orange Peel Extract

Abstract

Silver nanoparticles (AgNPs) were prepared in a one-step microwave-assisted synthesis guided by the principles of green chemistry. Microwave parameters were optimized using the Box–Benhken design for three factors (time, temperature, and pressure). Aqueous extracts from the peels of citrus fruits (orange, grapefruit, tangelo, lemon, and lime) were used for the synthesis of AgNPs using microwave technology, though the synthesis of AgNPs was only successful using the orange peel extract. Nanospheres of TEM mean diameter (with standard deviation) of 7.36 ± 8.06 nm were successfully synthesized in 15 min by reducing Ag+ ions (from AgNO3) with orange peel extract, which also served as a capping agent. Creation of AgNPs was confirmed using UV–visible spectroscopy, fluorescence emission spectroscopy, powder X-ray diffraction, and transmission electron microscopy, while size analysis was gathered from both transmission electron microscopy as well as dynamic light scattering. Analysis of all citrus peel extracts by gas chromatography–mass spectrometry indicated that the putative compounds responsible for successful AgNP synthesis with orange extract were aldehydes. The creation of AgNPs using environmentally benign reagents in minimal time paves the way for future studies on AgNP toxicity without risking interference from potentially toxic reagents and capping agents.