Green synthesis of silver monometallic and copper-silver bimetallic nanoparticles using Kigelia africana fruit extract and evaluation of their antimicrobial activities

Abstract

Aqueous extract of Kigelia africana fruits have been utilized in the syntheses of silver nanoparticles (AgNPs) and copper-silver bimetallic nanoparticles (Ag-CuNPs). The synthesized nanoparticles have been characterized using UV-vis, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy/energy dispersive X-ray analysis (SEM/EDX), x-ray diffration (XRD) and transmission electron microscopy (TEM). The antimicrobial activities have been evaluated against both Grams-negative and Grams-positive strains of bacteria and fungus. The UV-vis and FTIR techniques revealed the formation of nanoparticles and the active components were adsorbed on the surface of the particles thereby stabilizing the nanoparticles. The SEM reveals uniform microspheres of AgNPs and anisotropic particles for AgCuNPs. TEM shows a particle size of 10 nm. The nanoparticles inhibit the growth of both Grams-negative and Grams-positive bacteria. The present nanoparticles synthesized from aqueous extract of K. africana fruits inhibits Klebsiella pneumoniae more than any of the antibiotics tested in this study. It competes very well with augmentin against Pseudomonas aeruginosa and with meropenem against Candida albicans with inhibition zones of 23 and 25 mm, respectively. The bimetallic nanoparticles have demonstrated effectiveness against Staphylococcus aureus, with maximum inhibition zone of 27 mm.

Green synthesis of silver nanoparticles using plant extracts and their antimicrobial activities: a review of recent literature

“…Moreover, this process for AgNPs synthesis is economic, time efficient and straight forward. Phoenix dactylifera , 228 strawberry, 229 Ginseng-berry, 230 Kigelia africana 231 and Chaenomeles sinensis 232 fruit extract were also successfully utilized for the green synthesis of spherical AgNPs with high antimicrobial activity. Ginseng-berry fruit extract derived AgNPs showed greater ZOI against S. aureus (12.3 mm) compared to E. coli (11 mm).…”

Green synthesis of silver nanoparticles mediated by traditionally used medicinal plants in Sudan

“…In the current work, most of SPR peaks are within the anticipated wavelength range, however, some researchers have reported SPR peaks below 400 nm for their synthesized nanoparticles [9,15,31,41,42]. The absorbance bands below 400 nm are probably due to absorption of silver ions, complexes, impurities and plant phytochemicals.…”

“…It is evident that the stability of plant metabolites requires working at ambient temperature. However, to shorten the synthesis time and enhance complete conversion of Ag + to Ag 0 , some researchers have attempted synthesis at higher temperatures [8,9,14,[28][29][30][31][32][33]. Interestingly, Krishnan et al has synthesized silver nanoparticles from Piper nigrum at room temperature, 40, 60 and 80 °C and studied the surface plasmon resonance (SPR) of the resultant nanoparticles by UV spectroscopy and found that nanoparticles synthesized at 80 °C gave an intense surface plasmon resonance band [28].…”

AgCu NP Formation by the Ag NP Catalysis of Cu Ions at Room Temperature and Their Antibacterial Efficacy: A Kinetic Study

“…The main issues of AgCu NA preparation are high antibacterial efficacy, low toxicity, and high stability, which are strongly associated with the physicochemistry of the NAs and their stabilizers [ 23 ]. A recent study showed that biosynthesized AgCu NAs might have even better antibacterial efficacy [ 7 , 9 , 24 , 25 , 26 , 27 , 28 ]. These studies used plant extracts to synthesize AgCu NAs or bacteria to reduce Ag + and Cu 2+ and stabilize the AgCu NAs [ 12 , 29 ].…”