Biological mediated Ag nanoparticles from <i>Barleria longiflora</i> for antimicrobial activity and photocatalytic degradation using methylene blue

Abstract

The present study focuses on extraction of green synthesized silver nanoparticles (Ag-NPs) from Barleria longiflora L. leaves for antibacterial and photocatalytic activities. The extracted Ag-NPs have been characterized by XRD, FTIR, FE-SEM with EDX, HR-TEM accompanied SAED pattern and UV-Visible absorption spectroscopic techniques. Spectral studies confirmed the UV-Visible absorption spectrum of the Ag-NPs at a wavelength of 443 nm and a good crystalline nature with a face-centered cubic crystal structure using XRD spectrum. Surface topography and the presence of Ag in the prepared sample have been confirmed from SEM and EDX measurements. Various functional groups present in the sample have been examined using FT-IR spectroscopic analysis. A homogeneous dispersion of spherical form nanoparticles with a usual size of 2.4 nm was confirmed by visualization using FE-SEM and HR-TEM. Moreover, Ag-NPs stimulate a strong inhibition of Enterococcus sp., Streptococcus sp, Bacillus megaterium, Pseudomonas putida, Pseudomonas aeruginosa and Staphylocouus aureus; with a good catalytic reduction activity for degrading organic methylene blue (MB) dye. Therefore, silver nanoparticles obtained from Barleria longiflora L. have potential application in medicine and photocatalytic dye degradation processes.