Microwave-Assisted Green Synthesis of Silver Nanoparticles\nUsing Orange Peel Extract

Abstract

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