Biogenic synthesis and characterization of silver nanoparticles using aqueous leaf extract of Scoparia dulcis L. and assessment of their antimicrobial property

Designing Green Synthesis-Based Silver Nanoparticles for Antimicrobial Theranostics and Cancer Invasion Prevention

Introduction

Researchers are increasingly favouring the use of biological resources in the synthesis of metallic nanoparticles. This synthesis process is quick and affordable. The current study examined the antibacterial and anticancer effects of silver nanoparticles (AgNPs) derived from the Neurada procumbens plant. Biomolecules derived from natural sources can be used to coat AgNPs to make them biocompatible.

Methods

UV-Vis spectroscopy was used to verify the synthesis of AgNPs from Neurada procumbens plant extract, while transmission electron microscopy (TEM), photoluminescence (PL) spectroscopy, dynamic light scattering (DLS), and Fourier transform infrared spectroscopy (FTIR) were used to characterize their morphology, crystalline structure, stability, and coating.

Results

UV-visible spectrum of AgNPs shows an absorption peak at 422 nm, indicating the isotropic nature of these nanoparticles. As a result of the emergence of a transmission peak at 804.53 and 615.95 cm-1 in the spectrum of the infrared light emitted by atoms in a sample, FTIR spectroscopy demonstrated that the Ag stretching vibration mode is metal-oxygen (M-O). Electron dispersive X-ray (EDX) spectral analysis shows that elementary silver has a peak at 3 keV. Irradiating the silver surface with electrons, photons, or laser beams triggers the illumination. The emission peak locations have been found between 300 and 550 nm. As a result of DLS analysis, suspended particles showed a bimodal size distribution, with their Z-average particle size being 93.38 nm.

Conclusion

The findings showed that the antibacterial action of AgNPs was substantially (p≤0.05) more evident against Gramme-positive strains (S. aureus and B. cereus) than E. coli. The biosynthesis of AgNPs is an environmentally friendly method for making nanostructures that have antimicrobial and anticancer properties.

Review green synthesis of silver nanoparticles by using plant extracts and their antimicrobial activity

Interest in the biosynthesis of nanoparticles has increased in the last era by researchers. Nanoparticles have several applications in different fields like optoelectronics, magnetic devices, drug delivery, and sensors. Nanoparticle synthesis by green methods is safe for the environment and should be explored and encouraged popularly since various plants' have the high extent to form these nanoparticles. Worldwide, UV spectroscopy, X-ray diffraction, Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Dynamic Light Scattering (DLS), Atomic Force Microscopy (AFM) besides Fourier Transform Infrared Spectroscopy (FTIR) are used in many ways for characterize nanoparticles. The most advantageous use of AgNPs is their great attribution to be used as antimicrobial agents. Finally, concept of AgNPs synthesis is deserved to be the modern technical and medical concern. The current review shows a complete comprehensive and analytical survey of the biosynthesis of AgNPs with a particular focus on their activities as antimicrobials and the possible theories of their effect on the microbial cell and all influenced secondary metabolites.

Mapping the Progress in Surface Plasmon Resonance Analysis of Phytogenic Silver Nanoparticles with Colorimetric Sensing Applications

Nanotechnology is gaining enormous attention as the most dynamic research area in science and technology. It involves the synthesis and applications of nanomaterials in diverse fields including medical, agriculture, textiles, food technology, cosmetics, aerospace, electronics, etc. Silver nanoparticles (AgNPs) have been extensively used in such applications due to their excellent physicochemical, antibacterial, and biological properties. The use of plant extract as a biological reactor is one of the most promising solutions for the synthesis of AgNPs because this process overcomes the drawbacks of physical and chemical methods. This review article summarizes the plant-mediated synthesis process, the probable reaction mechanism, and the colorimetric sensing applications of AgNPs. Plant-mediated synthesis parameters largely affect the surface plasmon resonance (SPR) characteristic due to the changes in the size and shape of AgNPs. These changes in the size and shape of plant-mediated AgNPs are elaborately discussed here by analyzing the surface plasmon resonance characteristics. Furthermore, this article also highlights the promising applications of plant-mediated AgNPs in sensing applications regarding the detection of mercury, hydrogen peroxide, lead, and glucose. Finally, it describes the future perspective of plant-mediated AgNPs for the development of green chemistry.

Antifungal Activity of Juglans-regia-Mediated Silver Nanoparticles (AgNPs) against Aspergillus-ochraceus-Induced Toxicity in In Vitro and In Vivo Settings

Aflatoxins produced by some species of Aspergillus are considered secondary toxic fungal by-products in feeds and food. Over the past few decades, many experts have focused on preventing the production of aflatoxins by Aspergillus ochraceus and also reducing its toxicity. Applications of various nanomaterials in preventing the production of these toxic aflatoxins have received a lot of attention recently. The purpose of this study was to ascertain the protective impact of Juglans-regia-mediated silver nanoparticles (AgNPs) against Aspergillus-ochraceus-induced toxicity by exhibiting strong antifungal activity in in vitro (wheat seeds) and in vivo (Albino rats) settings. For the synthesis of AgNPs, the leaf extract of J. regia enriched with high phenolic (72.68 ± 2.13 mg GAE/g DW) and flavonoid (18.89 ± 0.31 mg QE/g DW) contents was used. Synthesized AgNPs were characterized by various techniques, including TEM, EDX, FT-IR, and XRD, which revealed that the particles were spherical in shape with no agglomeration and fine particle size in the range of 16-20 nm. In vitro antifungal activity of AgNPs was tested on wheat grains by inhibiting the production of toxic aflatoxins by A. ochraceus. According to the results obtained from High-Performance Liquid Chromatography (HPLC) and Thin-Layer Chromatography (TLC) analyses, there was a correlation between the concentration of AgNPs and a decrease in the production of aflatoxin G1, B1, and G2. For in vivo antifungal activity, Albino rats were administrated with different doses of AgNPs in five groups. The results indicated that the feed concentration of 50 µg/kg feed of AgNPs was more effective in improving the disturbed levels of different functional parameters of the liver (alanine transaminase (ALT): 54.0 ± 3.79 U/L and aspartate transaminase (AST): 206 ± 8.69 U/L) and kidney (creatinine 0.49 ± 0.020 U/L and BUN 35.7 ± 1.45 U/L), as well as the lipid profile (LDL 22.3 ± 1.45 U/L and HDL 26.3 ± 2.33 U/L). Furthermore, the histopathological analysis of various organs also revealed that the production of aflatoxins was successfully inhibited by AgNPs. It was concluded that the harmful effects of aflatoxins produced by A. ochraceus can be successfully neutralized by using J. regia-mediated AgNPs.

Preparation and characterization of biogenic silver nanoparticles using Strobilanthes cordifolia (Vahl) J.R.I.Wood leaves and its Biological applications

In the present study aqueous leaf extract of Strobilanthes cordifolia J.R.I.Wood was combined with silver nitrate to synthesis silver nanoparticles (AgNPs).The AgNPs was Characterized using visible spectroscopy (UV), X-ray diffraction(XRD), fourier transform infrared spectrophotometer (FTIR), scanning electron microscope (SEM), energy dispersive X-ray (EDaX), particle size analysis and transmission electron microscope (TEM).The UV spectrum absorption peak occurred at 438nm. The FTIR analysis of the AgNPs indicated the presence of functional groups such as aldehyde, alkenes and carboxylic acids.The crystalline structure of AgNPs was confirmed by XRD. The AgNPs have a spherical shape according to SEM. The AgNPs components composition was confirmed by EDaX.The particle size distribution of AgNPs is monodispersion in the range at 42.54nm.TEM demonstrated that the AgNPs size to be between 11.35-34.90nm.The AgNPs exhibited good antibacterial against Escherichia coli and Staphylococcus aureus. The antioxidant activity of the AgNPs was represented by increased DPPH, ABTS and H₂ O₂ activities.The antidiabetic activity of the AgNPs was indicated by the inhibition of α-amylase and α-glycosidase and anti-inflammatory highest albumin denaturation and HRBC membrane stabilization properties. Further, the AgNPs also significantly inhibited the MCF-7 cell lines. These results clearly suggest that the synthesized AgNPs using S. cordifolia leaves could have several potential biomedical applications. This article is protected by copyright. All rights reserved.

Biosynthesis of novel metallic silvers on kraft papers using cephalotaxus harringtonia fruit extract as a sustainable stabilizing agent (KP@AgNP)

Greenly synthesized silver nanoparticles (AgNPs) on different cellulosic materials show tremendous potential for colorful, biocidal, and reasonably strong products by replacing the traditional chemical-based synthesis protocols. This study reports on a novel in situ synthesis protocol for synthesizing green and sustainable AgNPs over cellulosic kraft paper substrates using a bio-based stabilizing agent (Cephalotaxus harringtonia fruit extract). The protocol could play a significant role in packaging industries. The aqueous extracts of Cephalotaxus harringtonia fruits have been used to synthesize the metallic silver. The deposited AgNPs values were investigated through XRF (X-ray fluorescence) analysis. The number of deposited nanoparticles (NPs) was 268 ± 7, 805 ± 14, and 1,045 ± 16 PPM, respectively for 0.5, 1.5, and 2.5 mm silver precursors. The developed products were tested with SEM (scanning electron microscopy), SEM-mediated elemental mapping, EDX (energy disruptive X-ray), FTIR (Fourier transform infrared spectroscopy), and XRD (X-Ray diffraction). XRD analysis further confirmed the presence of peaks for elemental AgNP on the deposited papers. Colorimetric values were measured to confirm the colorful appearances of the developed metallic silvers. Mechanical properties were tested in terms of the tensile index and bursting index. Moreover, the statistical analysis of coefficient of variations (R²) and a post-hoc ANOVA test that adopted the Newman-Keul methodology also confirm the significance of developed nanoparticles in the papers. The shielding capacity against UV light was also investigated; all the AgNPs-treated products provided values higher than 40, demonstrating the strong UV resistance capability of the kraft paper material. Overall, the study confirms a successful development of green AgNPs on paper materials.

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

Synthesis of metal nanoparticles using plant extracts is one of the most simple, convenient, economical, and environmentally friendly methods that mitigate the involvement of toxic chemicals. Hence, in recent years, several eco-friendly processes for the rapid synthesis of silver nanoparticles have been reported using aqueous extracts of plant parts such as the leaf, bark, roots, etc. This review summarizes and elaborates the new findings in this research domain of the green synthesis of silver nanoparticles (AgNPs) using different plant extracts and their potential applications as antimicrobial agents covering the literature since 2015. While highlighting the recently used different plants for the synthesis of highly efficient antimicrobial green AgNPs, we aim to provide a systematic in-depth discussion on the possible influence of the phytochemicals and their concentrations in the plants extracts, extraction solvent, and extraction temperature, as well as reaction temperature, pH, reaction time, and concentration of precursor on the size, shape and stability of the produced AgNPs. Exhaustive details of the plausible mechanism of the interaction of AgNPs with the cell wall of microbes, leading to cell death, and high antimicrobial activities have also been elaborated. The shape and size-dependent antimicrobial activities of the biogenic AgNPs and the enhanced antimicrobial activities by synergetic interaction of AgNPs with known commercial antibiotic drugs have also been comprehensively detailed.

Silver Nanoparticles Ecofriendly Synthesized by Achyranthes aspera and Scoparia dulcis Leaf Broth as an Effective Fungicide

This study describes an inexpensive, simple and green method to form silver nanoparticles from different leaf extracts of Achyranthes aspera and Scoparia dulcis plants. The silver nitrate is reduced by Achyranthes aspera and Scoparia dulcis leaf extracts respectively to generate two silver nanoparticle types symbolized as AA.AgNPs and SD.AgNPs. The optical absorption, size and morphology of silver nanoparticles are significantly impacted by extract types. The ultraviolet visible spectrum of AA.AgNPs shows a 433-nm peak being more broadened than that of SD.AgNPs. The Fourier infrared transform spectra of two of these silver nanoparticles revealed that their surface is modified by organic constituents from extracts, and thus they are stabilized in solution without any additional reaction. Images from transmission electron microscopy and scanning electron microscope indicate that AA.AgNPs are in clusters with the size of 8–52 nm almost possessing oval shape, while SD.AgNPs are smaller size of 5-45 nm separated well in diversified shapes (spherical, triangle, quadrilateral and hexagonal). Moreover, both AA.AgNPs and SD.AgNPs exhibit the highly antifungal effect against Aspergillus niger, Aspergillus flavus and the most strong impact on Fusarium oxysporum. For these obtained results, two new silver nanoparticles are promising fungicides for various applications of medical and agricultural fields.

Biosynthesis of silver nanoparticles by Fusarium scirpi and its potential as antimicrobial agent against uropathogenic Escherichia coli biofilms

The ability of Uropathogenic Escherichia coli (UPEC) to form biofilms, can be considered an important factor that contributes to the prevalence of Urinary Tract Infections (UTIs) due to the inaccessibility of the antibiotics into the highly complex structure of the biofilm. Moreover, with the appearance of antibiotic multiresistant UPEC strains, the alternatives of treatment of UTIs are less. Silver nanoparticles (AgNPs) can be useful in the treatment of the UPEC infections due to its physicochemical properties that confer them antibacterial activity against both planktonic and biofilm structured cells. A diversity of biological methods for synthesis of AgNPs with antimicrobial activity has been widely investigated during the last decades, between these methods; the fungal-biosynthesis of AgNPs highlights as an ecofriendly, scalable and low cost method. In this study, biogenic AgNPs were synthesized with extracellular metabolites secreted by the soil fungal strain Fusarium scirpi (Ag0.5–5) by an ecofriendly, simple and efficient method. The antimicrobial activity of the biosynthesized AgNPs against UPEC was evaluated. The Minimal Inhibitory Concentration (MIC) of biogenic AgNPs over planktonic UPEC cells was 25 mg/mL, whereas a sub-MIC concentration (7.5 mg/L) was sufficient to inhibit the UPEC-biofilm formation about a 97%, or produce the disruption of an 80% of mature UPEC-biofilms demonstrating the potential of fungal-derived AgNPs to prevent UPEC infections.