Biosynthesized silver nanoparticles from aqueous extracts of sweet lime fruit and callus tissues possess variable antioxidant and antimicrobial potentials

Different plant extracts have been utilized for biological synthesis of metal nanoparticles. However, no published literature compares the antimicrobial potential of silver nanoparticles (AgNPs) derived from extracts of mature fruit juice (SLF-AgNPs) versus callus (SLC-AgNPs) tissue of same plant. These SLF- and SLC-AgNPs exhibited variable physical and biological properties. Distinct UV-Vis absorption peak (at 250 nm) for SLF-AgNPs indicated formation of small-sized monodisperse particles. Both SLF-AgNPs (5 to 35 nm) and SLC-AgNPs (3 to 270 nm) exhibited quasi-spherical shapes. The FT-IR spectra showed occurrence of shared peaks at 3335, 1647, and 1080 cm(-1) while SLC specific peaks at 1065, 1042 and 1017 cm(-1). The SLF-AgNPs possessed higher DPPH free radical scavenging potential. These nanoparticles also showed better antibacterial and antimycotic action epitomized as higher inhibition zone diameters compared to SLC-AgNPs. This work can be furthered to identify predominant mechanism for improved antimicrobial potential of the synthesized AgNPs.