Antimicrobial activity of Zn-nanoparticles synthesized by leaf extract of Capparis spinosa

Abstract

In the last 2 decades, nanotechnology has developed significantly. It is now easy to perform materials reduction to a nano size called nanoparticles (NPs). One significant development is the use of plant extracts containing phytochemical compounds as reducing agent. Capparis spinosa, a shrub plant, was used in the synthesis of zinc oxide and iron oxide NPs. Synthesis and characterization of ZnONPs by consumed phytochemical compounds of C.spinosa leaf extract was performed. Synthesize ZnONPs from the aqueous leaf extract and characterize them using FT-IR, DLS and STEM and investigate the antimicrobial activity of NPs using agar well diffusion and the minimum inhibitory concentration (MIC). The aqueous leaf extract of C.spinosa contain flavonoids, alkaloids, tannin, phenol and saponin. FT-IR analysis showed peaks in C spinosa extract and ZnONPs spectra where different functional groups with unique peaks for ZnONPs were detected indicating the formation of specific bonds. DLS spectroscopy revealed polydispersity index (PDI) values of 0.638 for ZnONPs and STEM images for ZnONPs showed irregular NPs with sizes ranging from 33.75 to 89.14 nm. Antimicrobial test by agar well diffusion showed an inhibition zone of ZnONPs against all test microbial genera except C. glabrata and higher effect was against P.vulgaris with diameter of inhibition zone equal to 15.5± 0.7 mm. The MIC values of ZnONPs against P.vulgaris and C.Kruesi were the same (0.25mg/ml) while S.aureus, S.pyogens and C.glabrata showed less MIC value (0.125mg/ml). In conclusion, green synthesized ZnONPs showed an antimicrobial effect on skin associated microbial which can be adopted and developed with the aim of using it as an alternative to completely chemically synthesized antibiotics.