Green Synthesis of Silver Nanoparticles Using Nigella sativa Callus and Cellular Suspension Cultures with Different pH Values

Abstract

The current study included an extensive protocol for the first time globally. This protocol was concerned with the green synthesis of silver nanoparticles (AgNPs) from Nigella sativa callus and cellular suspended cultures. The results confirmed the success of the process of green synthesis of AgNPs from Nigella sativa callus by the color change in the reaction solution from colorless to brown and reddish-brown as a result of the reduction of Ag ions in the extract after addition of AgNO3 solution (1:1 v/v). UV-Vis spectroscopy was used to initially prove the existence of AgNPs, which showed an absorption peak ranging between (420-440 nm) caused by the phenomenon of Surface Plasmon Resonance (SPR) of AgNPs. (SEM) showed nanoparticle objects ranging from (18.341 - 40.932) nm for standard extracts and (17.261 - 29.13) nm for suspended cultures extracts. (EDX) proved the success of producing AgNPs in different proportions depending on the type of tissue cultures used and the difference in the pH value of the extracts (6, 9, 12), as the highest % of AgNPs production reached 4.46% in suspended cultures extracts from pH 12, followed by callus extracts, which reached 4.12% at pH 12. biologically prepared AgNPs proved their effectiveness in inhibiting the growth of Gram+ and Gram- bacteria, as the inhibition zone ranged (19– 35 mm) depending on the type of extract and the degree of acidity (pH) applied to the extract.