Green Synthesis, Characterization and Antimicrobial Activity of Silver Nanoparticles Produced fromFumaria officinalis L. Plant Extract

Abstract

Synthesis of silver nanoparticles using plant extract of Fumaria officinalis L., (AgNPs-E), as a reducing and capping agent, is presented in this study. Formation of AgNPs-E is monitored by measuring surface plasmon resonance (SPR) absorption band in the UV-VIS range 200–800 nm. Based on UV-VIS spectra, the SPR band of AgNPs-E obtained by synthesis at the room and boiling temperatures appeared at 438  and 440 nm, respectively. After 15 days of equilibration, the SPR band was slightly shifted by 6 nm indicating a good stability of the formed complex at room temperature. The bands in the range 200–400 nm, originating from π−π* and n−π* transitions in the extract, disappeared in the spectra of AgNPs-E after reduction. Morphology, size and shape of formed AgNPs-E were investigated by scanning electron microscopy. The presence of both elemental silver and its crystalline structure (face centered cubic type) in AgNPs-E was confirmed by the energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD) analyses. Particles size was determined by the XRD analysis: 20 ± 1 and 18 ± 1 nm at room (sample 1) and boiling temperature (sample 2), respectively. Fourier transform infrared spectroscopy (FTIR) assessments were carried out to identify biomolecules of F. officinalis responsible for the reduction and capping of the bioreduced silver nanoparticles and to predict their role in silver nanoparticles synthesis. FTIR spectroscopy indicated the activity of different functional groups during the synthesis by the changes in ν_C–OH, δ_OH, ν_C–O–C and (NH)C=O modes in the AgNPs-E spectrum relative to that of the extract. The AgNPs-E particles showed strong antibacterial activity against Staphylococcus aureus ATCC 25923, Bacillus cereus ATCC 11778, Bacillusluteus in haus strain, Bacillus subtilis ATTC 6633, Listeria monocytogenes ATCC 15313, Escherichia coli ATTC 25922, Pseudomonas aeruginosa ATTC 27853, Klebsiella pneumoniae ATTC 700603, Proteus vulgaris ATTC 8427, and antifungal activity against Candida albicans ATTC 2091.