38 nm. Recently, Sathiya and Akilandeswari [26] reported that the particle size distribution of silver nanoparticles synthesized by Delonix elata leaf broth shows that particles are polydisperse mixture, with average diameter 70.01 nm. Figure 5 Size distribution analysis of AgNPs was determined by dynamic light scattering. The particle size distribution

analysis revealed that the average particle size was approximately 5 nm. Size and morphology analysis of AgNPs using TEM TEM is one of the most valuable tools to directly analyze structural information of the nanoparticles. TEM was used to obtain essential information on primary nanoparticle size and morphology [40]. TEM micrographs of the AgNPs revealed

distinct, uniformly spherical shapes that were well separated from each other. The average particle size was estimated from measuring more than 200 particles from TEM images, and showed particle sizes Napabucasin molecular weight between 2 and 10 nm with an average size of 5 nm (Figure 6). Shankar et al. [38] reported that the size of the nanoparticles produced by geranium leaf extract was from 16 to 40 nm. The nanoparticles obtained from leaf extracts of Catharanthus roseus showed with an average size of 27 to 30 nm. Rodríguez-León et al. [41] synthesized two different populations of nanoparticles such as small in size with an average diameter around 3 to 5 nm and another one larger in size between 10 to 20 nm using different concentrations of leaf extract and AgNO3. Figure 6 Determination TSA HDAC price of size and shape of AgNPs. The size and morphology of AgNPs were determined using transmission electron microscopy. TEM micrograph of AgNPs prepared SPTLC1 from A. cobbe (A). The average particle size was found to be 5 nm. Particle size distributions from TEM images (B). Determination of MIC and sublethal concentration of AgNPs and antibiotics The MIC (Table 1) and sublethal concentration

(Table 2) of each test strain of bacteria were first determined against antibiotics and AgNPs alone. The results showed that the effective doses were different between Gram-negative and Gram-positive bacteria, with the Gram-negative P. aeruginosa and S. flexneri found to be more susceptible to AgNPs. In contrast, AgNPs were comparatively less effective against the Gram-positive S. aureus and S. pneumoniae. This discrepancy could be due to differences in the membrane structure and the composition of the cell wall, thereby affecting access of the AgNPs. The cell walls of both Gram-positive and Gram-negative bacteria have an overall negative charge because of the presence of teichoic acids and lipopolysaccharides, respectively [42]. The potent bactericidal activity of AgNPs against P. aeruginosa and S. flexneri could be due to strong PF-3084014 chemical structure interactions between cationic plant compounds and the negatively charged cell wall components.