Biogenic Synthesis and Characterization of Gold Nanoparticles from Morus alba L. Leaves by Microwave Extraction Method

The aim of this study was to investigate the rapid, simple, and inexpensive biosynthesis and characterization of gold nanoparticles (AuNPs) an extract from leaves of Morus alba L. The generated gold nanoparticles were characterized by UV-Vis spectroscopy, TEM, FT-IR and zeta-sizer. For the biogenesis of gold nanoparticles, Morus alba L. (Mulberry) leaves and HAuCl4.3H2O solution were utilized as the starting ingredients. Fresh leaves of Morus alba L. were collected from Turkey (Trabzon). 100 mL of distilled water was mixed with 10 g of dried material for 120 minutes. The mixture was then extracted using a laboratory microwave for 4 minutes at 600 W. For the biosynthesis of AuNPs, different amounts 100 ml of (0.5 mM, 1 mM) aqueous HAuCl4.3H2O solution of leaf extract (0.5 and 1 mL) were mixed with HAuCl4. 3H2O solution, and then the mixture was placed in a household microwave at 90 W for 1 to 30 minutes. UV-vis spectroscopy, TEM, FT-IR and zeta-sizer were performed to characterize the produced gold nanoparticles. UV-Vis absorption spectra was measured using a Shimadzu UV-1240 UV-Vis spectrophotometer with a wave length range of 300 to 800 nm. The development of AuNPs was indicated by the mixture's purple-red colour. From the results of zetasizer study, the average particle size of the AuNPs was 78.95±0.57 nm, the zeta potential was 12.9±0.808 mV, and the polydispersity index was 0.321±0.004. When the AuNP solutions were kept in the refrigerator, their UV-Vis absorption spectra rarely changed and remained stable for around 2 to 2.5 months.