Phyto-fabrication of silver nanoparticles by Acacia nilotica leaves: Investigating their antineoplastic, free radical scavenging potential and application in H ₂ O ₂ sensing

In this study, a green approach by utilizing Acacia nilotica leaves (ANL) extract to produce silver nanoparticles (AgNPs) has been made. The biosynthesized AgNPs displayed surface plasmon resonance (SPR) centered at 430 nm. Fourier transform infrared spectroscopy (FTIR) and energy-dispersive spectra (EDS) results showed the contribution of phyto-constituents of ANL in the reduction, capping and stabilizing matrix for AgNPs. The AgNPs were characterized by X-ray diffraction (XRD), and high resolution transmission electron microscopy (HR-TEM) revealed the synthesized ANL-AgNPs were crystalline and spherical forms having about ∼20 nm average particle size. ANL-AgNPs exhibited significant antineoplastic efficacy towards SKOV3 ovarian cancer cells (LD ₅₀ ; 66.5 µg/mL) thus could be useful to treat the cancer and to trounce limitations of conventional chemotherapy treatment. The synthesized AgNPs unveiled substantial antioxidant activity represented by common enzyme markers 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) (IC ₅₀ ; 48.4 µg/mL) and 2,2-Diphenyl-1-picrylhydrazyl (DPPH) (IC ₅₀ ; 55.2 µg/mL) activity. The ANL-AgNPs displayed substantial anti-bacterial activity against human pathogenic bacterial strains and also studied their minimum inhibitory and minimum bactericidal concentration (MIC and MBC) for individual strain. Additionally, the synthesized ANL-AgNPs exhibited colorimetric detection of hydrogen peroxide (H ₂ O ₂ ) with better selectivity which showed its viability in determining reactive oxygen species in biological and environmental samples. Overall, the ANL-AgNPs could be used in multitasking biomedical applications, including anticancer, antioxidant, and antibacterial potential and also in sensing application.