Hafr Al Batin Phoenix dactylifera L. Leaves Extract as Efficient Catalyst for Green Synthesis of New Silver Nanoparticles with Broad Spectrum Antimicrobial Activity: Characterization and Evaluation Compared to Fungi
摘要
Research work on biosynthesis of bioactive silver nanoparticles from green sources continues to provide valuable new materials, that can be applied in the field of medicine against pathogens. In this context, for the first time the extract of date palm leaves (DPL) (Phoenix dactylifera L.) of Hafr Al Batin City was utilized as new catalytic agent for the biosynthesis of AgNPs and compared to Aspergillus niger NRC24 filtrate. All nanoparticles were characterized by UV–visible spectrophotometry, transmission electron microscopy and dynamic light scattering. DPL-AgNPs showed a characteristic plasmon beaks with well-dispersed cubic to spherical shape particles of good sizes ranged around 12.86–97.90 nm and 7.40–26.92 nm at pH 8 and pH 10, respectively. Fungal-AgNPs exhibited a surface plasmon resonance at wavelengths 405 nm and 425 nm, with spherical to elliptical shapes in the range of 7.40–23.82 nm and 5.21–20.36 nm, respectively. Intensity-Weighted Gaussian Distribution of DPL-AgNPs was 67.1 and 77.5 nm, respectively, with Zeta potential as − 40.23 and − 35.455 mv, respectively, that is referred to their long-term stability. DPL-AgNPs prepared by using 4 mM AgNO3 at pH10 showed a broad spectrum inhibition against pathogenic Gram-positive bacteria, S. aureus and B. subtilis (16 mm), Gram-negative bacteria, E. coli (22 mm) and S. enterica (17 mm), Yeast C. albicans (21 mm) and filamentous fungi A. niger (18 mm). DPL-AgNPs prepared by using 2 mM AgNO3 at pH 10 showed only an antifungal inhibition of 15 mm against C. albicans and inhibition of 13 mm against A. niger. Biological activity of DPL-AgNPs suggests their application in medicine as antibacterial and antifungal agents.