Green Synthesis of Silver Nanoparticles with Dalbergialatifolia Plant Leaves as Reductant and Its Antimicrobial Properties

Abstract

Green synthesis of nanoparticles has evolved as a low-cost environment friendly, non-toxic and large scale up process. This investigation was carried out on the synthesis of AgNPs using Dalbergialatifolia (DL) aqueous plant leaves extract for the bioreduction of silver ions to nanoparticles, with AgNO3 as the precursor. The bioreduction process was carried out varying certain operational parameters; pH, reaction time, AgNO3 concentration and ratio of extract to silver nitrate solution. UV-Vis spectrophotometer was used to monitor the reaction. Characterization of the synthesized AgNPs was done using Ultravisible/Visible Spectrophotometer (Uv/Vis), Fourier Transform Infra-Red (FTIR), X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM) analyses. The surface plasmon resonance (SPR) band for the AgNPs was observed to be at 450nm. The optimum conditions for the synthesis of AgNPs with the plant extract were obtained to be; 45 minutes synthesis time, acidic pH, 1mM AgNO3 concentration and ratio 1:1 of plant extract to AgNO3 solution. FTIR analysis for the plant extract revealed the presence of O-H, C=O, C-H, C-N, N-H functional groups as well as the benzyl ring which are found in compounds like flavonoids, phenols and terpenoids. The characteristic peaks for these functional groups were also observed in the synthesized AgNPs, but had almost disappeared, which may indicate that these compounds, present in the plant extract were responsible for efficient reduction, capping and stabilization of the obtained AgNPs. SEM analysis revealed that the synthesized AgNPs were quassi spherical in shape and uniformly distributed. The XRD patterns of the AgNPs revealed Braggs reflections representing b111N, b200N, b220N and b311N planes for fc crystal structure for metallic silver with reference to the JCPDS data. Antimicrobial activity of the nanoparticles was studied against; Staphylococcusaureus, Esterichiacoli, Bacillussubtilus, Pseudomonasaeruginose, Klebsiella, Salmonellaetyphi, Candidaalbican, Aspergillusniger, Rhizophusstolomite and Penicilliumnotatum which in turn showed good inhibition against the microbes at both high and low concentrations. Dalbergialatifolia plant leaves extract proves to be a good option as reductant for AgNPs synthesis, and the synthesized AgNPs were found to be very effective antimicrobial agent.

Introduction

Nanotechnology involves manipulating materials at the nanoscale (1–100 nm), where their properties significantly differ from bulk materials due to their small size and large surface area. Nanoparticles are traditionally synthesized via physical and chemical methods, but green synthesis using natural biological agents like plant extracts offers an eco-friendly, cost-effective alternative. This biological approach controls nanoparticle size, shape, and stability, making it suitable for large-scale production.

The study focused on synthesizing silver nanoparticles (AgNPs) using aqueous extracts of Dalbergia latifolia leaves as reducing agents. The research optimized operational variables such as reaction time, concentration, pH, and extract-to-precursor ratio for efficient AgNP synthesis. Characterization was performed using UV-Vis spectroscopy, FTIR, SEM, and XRD, confirming successful formation of quasi-spherical, crystalline AgNPs stabilized by phytochemicals (flavonoids, terpenoids, alkaloids) in the plant extract.

Optimal conditions included a 1:1 ratio of extract to 1mM AgNO3, acidic pH, and a reaction time of 45 minutes. The synthesized AgNPs exhibited strong antibacterial and antimicrobial properties, suggesting potential applications in medicine, wound healing, and environmental disinfection.

Conclusion

This present investigation reports the green synthesis of AgNPs using D. latifoliaplant leaves extract. Certain operational parameters were varied to determine the optimum conditions for AgNPs synthesis. This plant-based nanotechnology is free from poisonous and dangerous solvents or wastes. Rapid synthesis of AgNPs was attained when some parameters, namely; time, pH, AgNO3 concentration and ratio of extract to AgNO3 were varied. The extracts served as reducing, capping and stabilizing agents in the synthesis. The method is a single step process with economic viability. This study revealed that D. latifolia leaves extract results to a high concentration of AgNPs and that the AgNPs were fully formed with the aqueous extract of D.latifoliain 45 minutes. Also, using ratio 1:1 of plant extract to AgNO3 solution gave the optimum ratio for the synthesis of AgNPs. Furthermore, this investigation revealed thata high concentration of AgNPs was formed with 1mM AgNO3 concentration. The present investigation also revealed that for optimum AgNPs synthesis with D.latifolia leaves extracts, the acidic medium is most preferable.

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Copyright © 2025 Ogundele Damilola Tope, Fasoranti Olusola Monisola, Ogunyemi Babatunde Tope. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.