Crystallographic structure, antibacterial effect, and catalytic activities of fig extract mediated silver nanoparticles

Abstract

Silver nanoparticles (Ag NPs) play a pivotal role in the current research landscape due to their extensive applications in engineering, biotechnology, and industry. The aim is to use fig (Ficus hispida Linn. f.) extract (FE) for eco-friendly Ag NPs synthesis, followed by detailed characterization, antibacterial testing, and investigation of bioelectricity generation. This study focuses on the crystallographic features and nanostructures of Ag NPs synthesized from FE. Locally sourced fig was boiled in deionized water, cooled, and doubly filtered. A color change in 45 mL 0.005 M AgNO₃ and 5 mL FE after 40 min confirmed the bio-reduction of silver ions to Ag NPs. Acting as a reducing and capping agent, the fig extract ensures a green and sustainable process. Various analyses, including UV-vis absorption spectrophotometry (UV), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Field emission scanning electron microscopy (FESEM), Energy dispersive X-ray spectroscopy (EDX) and Transmission electron microscopy (TEM) were employed to characterize the synthesized nanoparticles, and Gas chromatography-mass spectrometry (GC-MS) analysis of the fig extract revealed the presence of eleven chemicals. Notably, the Ag NPs exhibited a surface plasmon resonance (SPR) band at 418 nm, confirmed by UV analysis, while FTIR and XRD results highlighted the presence of active functional groups in FE and the crystalline nature of Ag NPs respectively. With an average particle size of 44.57 nm determined by FESEM and a crystalline size of 35.87 nm determined by XRD, the nanoparticles showed strong antibacterial activities against Staphylococcus epidermidis and Escherichia coli. Most importantly, fig fruit extract has been used as the bio-electrolyte solution to generate electricity for the first time in this report. The findings of this report can be the headway of nano-biotechnology in medicinal and device applications.

Keywords: Ag NPs; Antibacterial activity; Biosynthesis; FE-Electrochemical cell; Fig extract; Internal resistance; Voltage regulation.

Fig. 1

Schematic representation of the color changes for producing silver nanoparticles using FE.

Fig. 2

Shows Zn/Cu-based FE_BEC setup (a) without and (b) with load circuit.

Fig. 3

XRD pattern for green synthesis Ag NPs.

Fig. 4

Williamson–Hall analysis of Ag NPs.

Fig. 5

UV–Vis spectra of (a) Ag NPs, fig extract, DI water, AgNO₃, (b) Ag NPs, and (c) band gap analysis of Ag NPs.

Fig. 6

Displays the FT-IR spectra of Ag NPs and fig powder.

Fig. 7

Fig extract ethanol chromatogram by GCMS analysis.

Fig. 8

Shows the Ag NPs (a) FESEM pictures, (b) mean particle size histogram, (c) EDX data, and (d) weight (%) of the constituents.

Fig. 9

Ag NPs TEM pictures at various sizes: (a) 50 nm, (b) 10 nm, (c) SAED pattern, and (d) particle size histogram.

Fig. 10

Zeta potential distribution of FE mediated Ag NPs.

Fig. 11

Shows images (a, b) and bar graphs (c) comparing the antibacterial effects of silver nanoparticles and ethanol on specific bacteria.

Fig. 12

Shows a cell's electrical activity for (a) V_oc b) I_sc (c) maximum power, and (d) internal resistance.

Fig. 13

Illustrates the electrical behavior within the cells, depicting (a) load voltage, (b) load current, (c) voltage regulation, and (d) capacity for a load resistance of 6 Ω.

Fig. 14

Shows the average (a) energy and (b) voltage efficiency of 6 Ω load resistances.