Antioxidant, antibacterial, and catalytic performance of biosynthesized silver nanoparticles of Rhus javanica, Rumex hastatus, and Callistemon viminalis

Abstract

Rhus javanica (Anacardiaceae) containing abundant glucopyranosidal constituents, is traditionally used to treat gastric and duodenal ulcer, dysentery, and diarrhea. Rumex hastatus (Polygonaceae) widely distributed in Pakistan, has traditional importance in treating wound healing, jaundice, rheumatism, and skin diseases. Callistemon viminalis (Myrtaceae), a rich source of essential oils, saponins, triterpenoids, phloroglucinols, and flavonoids is used in industries, perfumes, nutrition, and cosmetics. Taking the importance of the subject plants, this study is designed to synthesize silver nanoparticles via aqueous extracts of R. javanica (RJAgNPs), R. hastatus (RHAgNPs), and C. viminalis (CVAgNPs). Synthesis, surface, and sizes of silver nanoparticles (AgNPs) were confirmed using spectroscopic techniques including ultraviolet-visible (UV-Vis), Fourier transform-infrared (FT-IR), and scanning electron microscopy (SEM). AgNPs were produced in ratios 1:15, 1:16, and 1:9 and inferred via appearance of a sharp surface plasmon resonance (SPR) absorption peak (400-435 nm), which represented well-defined, stable, and spherical AgNPs. From SEM analysis, the sizes of RJAgNPs, RHAgNPs, and CVAgNPs were found to be 67 nm, 61 nm, and 55 nm, respectively. The synthesized AgNPs exhibited potential free radical scavenging, antibacterial, and catalytic properties in degradation of dyes including Congo red, methylene blue, methyl orange, rhodamine B, ortho and para-nitrophenols, and several food colours. Hence, the subject AgNPs in the current study might display promising role in drug development and remediation of environmental/industrial effluents.

Keywords: AgNPs; Antibacterial; Callistemon viminalis; Rhodamine B; Rhus javanica; Rumex hastatus.

Fig. 1

(a) Rhus javanica, (b) Rumex hastatus, and (c) Callistemon viminalis plants used in this study for AgNPs synthesis.

Fig. 2

UV–Vis spectral graphs of RJAgNPs synthesized in 1:15 ratio at all four conditions.

Fig. 3

UV–Vis spectral graphs of RHAgNPs synthesized in 1:15 ratio at all four conditions.

Fig. 4

UV–Vis spectral graphs of RHAgNPs synthesized in 1:16 ratio at all four conditions.

Fig. 5

UV–Vis spectral graphs of RHAgNPs synthesized in 1:17 ratio at all four conditions.

Fig. 6

UV–Vis spectral graphs of CVAgNPs synthesized in 1:1 to 1:9 ratios at all four conditions.

Fig. 7

SEM images (a-c) and the particle size distribution graphs (d-f) of the synthesized RJAgNPs, RHAgNPs, and CVAgNPs.

Fig. 8

Antioxidant activity (DPPH and ABTS assays) of RJAE, RHAE, CVAE, RJAgNPs, RHAgNPs, and CVAgNPs.

Fig. 9

UV–Vis spectral graphs of the catalytic potential of RJAgNPs, RHAgNPs, and CVAgNPs in dyes, nitrophenols, and food colours reduction.

Fig. 9

UV–Vis spectral graphs of the catalytic potential of RJAgNPs, RHAgNPs, and CVAgNPs in dyes, nitrophenols, and food colours reduction.