Green synthesis of silver nanoparticles using Prosopis juliflora bark extract: reaction optimization, antimicrobial and catalytic activities

Figures & data

Figure 1. Visual observation of synthesis of AgNPs (A): (a) P. juliflora bark extract, (b) AgNO₃ before addition of extract and (c) after addition of extract depicting synthesis of AgNPs as the colour turns to light brown in colour. (B) UV-vis spectra of biosynthesized AgNPs.

Figure 2. UV-vis spectra of biosynthesized PJB-AgNPs recorded as a function of (A) time, (B) concentration of AgNO₃ solution, (C) concentration of extract, (D) temperature, (E) microwave and (F) after storage for 8 months.

Figure 3. Physicochemical characterization of PJB-AgNPs. (A) Representative DLS spectrum of AgNPs, here hydrodynamic radius is ∼55 nm, (B) zeta potential of AgNPs is −16 mV, (C) SEM of AgNPs, the size of nanoparticles is ∼10–50 nm, and (D) EDS pattern of AgNPs showing prominent peak of silver.

Figure 4. FTIR spectra of (A) P. juliflora bark extract and (B) biosynthesized PJB-AgNPs.

Figure 5. Antibacterial activity of PJB-AgNPs showing zone of inhibition of (A) E. coli and (B) P. aeruginosa. (C) Comparative graph for zone of inhibition of both. Here, kanamycin and autoclaved ddH₂O were taken as positive and negative control, respectively.

Figure 6. Anticancer activity against A549 cells treated with different concentrations of PJB-AgNPs, showing dose-dependent anticancer activity as determined by Alamar blue assay. (A) Untreated A549 cells as control and (B) A549 cells treated with PJB-AgNPs (C) Representative graph of anticancer activity.

Figure 7. Photocatalytic degradation of 4-nitrophenol using biosynthesized PJB-AgNPs.