scholarly journals Green Synthesis and Antibacterial Activity of HAp@Ag Nanocomposite Using Centella asiatica (L.) Urban Extract and Eggshell

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Xuan Nui Pham ◽  
Hoa Thi Nguyen ◽  
Ngan Thi Pham

In recent years, the green synthesis of nanoparticles via biological processes has attracted considerable attention. Herein, we introduce a facile and green approach for the synthesis of poriferous silver nanoparticles (Ag-NPs) decorated hydroxylapatite (HAp@Ag) nanoparticles with excellent antibacterial properties. All the nanocomposites were fully characterized in the solid state via various techniques such as X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and energy-dispersive X-ray spectrometer (EDX), in which the synthesized Ag-NPs (24 nm in diameter) and their homogeneous incorporation on HAp have been studied by ultraviolet-visible (UV-vis) technique, transmission electron microscopy (TEM), and dynamic light scattering (DLS) analysis. The obtained results indicate that the structure and morphology of HAp have no significant changes after the incorporation of Ag-NPs on its surface. Moreover, an impressive antibacterial activity of HAp@Ag nanocomposite against Gram-positive bacterium Staphylococcus aureus and Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa has been recorded by using the agar well diffusion method. As a result, the HAp@Ag nanocomposite promises to be a great biomedical material with high antibacterial properties.

2020 ◽  
Vol 35 (4-5) ◽  
pp. 389-398
Author(s):  
Tarık Eren ◽  
Gülay Baysal ◽  
Faik Doğan

There is a growing interest in new type of biocidal compounds with antibacterial properties against bacteria. In this study, new antibacterial synthetic materials bearing curcumin and cationic polymers were synthesized. In the synthesis stage, the methacrylate functional cationic monomer was synthesized via the Michael addition route by using 3-acryloxy-2-hydroxypropyl methacrylate and 3-amino pyridine to obtain Monomer 1. Monomer 1 was further quaternized with hexyl bromide to obtain a cationic methacrylate functional monomer. Free-radical polymerization of Monomer 1 and methyl acrylate was conducted in the presence of azobisisobutyronitrile under dimethylformamide solvent. The composite formulation was conducted by using turmeric extract Curcuma longa (curcumin), hydroxyapatite, montmorillonite, and silver nitrate. The materials were analyzed by using the methods of X-ray diffraction, nuclear magnetic resonance, Fourier transform infrared spectroscopy, and scanning electron microscopy. The biocidal activities against the bacteria Escherichia coli, Listeria monocytogenes, Salmonella, and Staphylococcus aureus were analyzed using agar well diffusion method. From the Fourier transform infrared, X-ray diffraction, and scanning electron microscopy analysis results of the synthesized nanocomposites, it is seen that they form strong connections with the components added to the composites and form an exfoliated structure. According to the antibacterial analysis results, the nanocomposites obtained have showed a strong antibacterial resistance against E.coli, L.monocytogenes, Salmonella, and S. aureus bacteria, and the high inhibition zone areas were obtained.


2016 ◽  
Vol 49 (2) ◽  
pp. 173-193 ◽  
Author(s):  
Mojtaba Abbasian ◽  
Farideh Mahmoodzadeh

Chitosan (Cts) was first modified with 4-cyano,4-[(phenylcarbothioyl)sulfanyl]pentanoic acid to serve as reversible addition–fragmentation chain transfer (RAFT) agent, and then the controlled grafting polymerizations of acrylic acid (PAA) were performed. The resultant copolymers were used as a stabilizing agent for preparation of colloidal silver nanoparticles (Ag NPs) in the range of 2–10 nm. Afterwards, montmorillonites (MMTs) were added to the solution of colloidal Ag NPs for improving thermal stability. Proton nuclear magnetic resonance spectroscopy, Fourier transform infrared spectrometry, energy dispersive X-ray spectroscopy, X-ray diffraction analysis, and scanning electron microscopy images demonstrate the successful synthesis of the graft copolymer. Their thermal behavior was examined by differential scanning calorimetry and thermogravimetric analyses.The antibacterial activity of Ag/Cts-g-PAA and Ag/Cts-g-PAA/MMT was investigated against Staphylococcus aureus, Escherichia coli, and Candida albicans by the disc diffusion method using Mueller Hinton agar. Antimicrobial tests show that Ag/Cts-g-PAA has much higher antimicrobial activity than Ag/Cts-g-PAA/MMT. This method would enable a wide variety of molecular designs to afford novel types of tailored hybrid materials composed of natural polysaccharides and synthetic polymers. The new hybrid materials were used as a stabilizing agent for preparation of Ag bionanocomposites with good antibacterial activity.


2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Tayyaba Naseem ◽  
Muhammad Akhyar Farrukh

Recently, development of reliable experimental protocols for synthesis of metal nanoparticles with desired morphologies and sizes has become a major focus of researchers. Green synthesis of metallic nanoparticles has accumulated an ultimate interest over the last decade due to their distinctive properties that make them applicable in various fields of science and technology. Metal nanoparticles that are synthesized by using plants have emerged as nontoxic and ecofriendly. In this study a very cheap and simple conventional heating method was used to obtain the iron nanoparticles (FeNPs) using the leaves extract ofLawsonia inermisandGardenia jasminoidesplant. The iron nanoparticles were characterized by thermal gravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray diffraction (XRD). The antibacterial activity was studied againstEscherichia coli,Salmonella enterica,Proteus mirabilis, andStaphylococcus aureusby using well-diffusion method.


Author(s):  
Subbiah Murugesan ◽  
Sundaresan Bhuvaneswari ◽  
Vajiravelu Sivamurugan

Objective: In the present system, the green synthesis of silver nanoparticles using marine the red alga Spyridia fusiformis and antibacterial activity was carried out.Methods: The seaweed extract was used for the synthesis of AgNPs at room temperature. The silver nanoparticles were characterized by using UV–Visible spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscope and X-ray diffraction (XRD) techniques. The antibacterial activity of biosynthesized silver nanoparticles was carried out by disc diffusion method against pathogenic bacteria.Results: The UV-visible spectroscopy revealed surface plasmon resonance at 450 nm. The FT-IR measurements showed the possible functional groups responsible for the formation of nanoparticles. The X-ray diffraction analysis showed that the particles were crystalline in nature. TEM micrograph has shown the formation of silver nanoparticles with the size in the range of 5–50 nm. The silver nanoparticles synthesized from the S. fusiformis showed higher activity and proved their efficacy in controlling the pathogenic bacterial strains. The nanoparticles showed highest inhibition activity on K. pneumaniae and S. aureus up to 26 and 24±0.01 mm at 100 μg/ml of nanoparticles.Conclusion: The synthesised AgNPs have shown the best antibacterial activity against human pathogens E. coli, K. pneumoniae, S. aureus and P. aeruginosa. The above eco-friendly AgNPs synthesis procedure could be a viable solution for industrial applications in the future and therapeutic needs.


2021 ◽  
Vol 3 (5) ◽  
Author(s):  
A. Diallo ◽  
N. Tandjigora ◽  
S. Ndiaye ◽  
Tariq Jan ◽  
I. Ahmad ◽  
...  

Abstract Nowadays, green synthesis of nanoparticles using plant precursors has been extensively studied. However, less attention has been given to Mn3O4. This contribution validates the synthesis of single-phase Hausmannite Mn3O4 nanoparticles by a green approach without using any standard acid/base compounds, surfactants, and organic/inorganic dissolving agents. The chemical chelation of the Mn precursor was performed via bioactive compounds of the Aspalathus Linearis’ extract, an African indigenous plant. Annealing at 400 °C for ~ 1 h was required to crystallize the small amorphous nanoparticles with an initial bimodal size distribution peaking at $$\left\langle {\phi_{1} } \right\rangle$$ ϕ 1  ~ 4.21 nm and $$\left\langle {\phi_{2} } \right\rangle$$ ϕ 2  ~ 8.51 nm respectively. Such annealing lead to increase in the diameter of the nanoparticles from 17 to 28 nm.The morphological, structural, vibrational, surface, and photoluminescence properties of the single-phase Hausmannite nanoparticles were comprehensively investigated by High Resolution Transmission Electron Microscopy(HRTEM),Energy Dispersive X-ray Spectroscopy (EDS), X-ray Diffraction (XRD), Raman and X-rays Photoelectron Spectroscopy (XPS), spectroscopy as well as room temperature photoluminescence. Structural and morphological investigations revealed the formation of quasi-spherical nanoparticles having a single phase Hausmannite Mn3O4 crystal structure. XPS results also validated the XRD results about the formation of Hausmannite Mn3O4 nanoparticles. Raman investigations allowed a crystal-clear distinction between the Mn3O4 nature of the nanoparticles from the potential γ -Mn2O3 phase as both phases belong to the same space group and both assume tetragonally-distorted cubic lattices of nearly similar dimensions. The optical studies of the single phase Hausmannite crystalline nanoparticles exhibited a broad photoluminescence in the spectral range of 300–700 nm, which is ideal for emission devices. Graphic abstract


2021 ◽  
Vol 8 (2) ◽  
pp. 51-56
Author(s):  
Behnaz Shokrollahi ◽  
Akram Sadat Tabatabaee Bafroee ◽  
Tayebeh Saleh

Background: Metal oxide nanoparticles (NPs) have shown promising efficacy for combating bacterial resistance due to their antibacterial properties. This research investigated the effect of zinc oxide NPs (ZnO-NPs) on the antibacterial activity of conventional antibiotics including ciprofloxacin (CIP), cefotaxime (CTX), and colistin (CST) against multidrug-resistant Acinetobacter isolates. Methods: The disc diffusion method was performed to detect the pattern of antibiotic resistance in isolates. The synthesized ZnO-NPs via the solvothermal method were characterized by field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), and energy-dispersive X-ray spectroscopy (EDS). Finally, the broth microdilution technique was conducted to demonstrate the antibacterial activity of CIP, CTX, and CST antibiotics with and without a sub-inhibitory concentration of ZnO-NPs. Results: XRD, EDS, and FESEM results confirmed the crystalline structure of ZnO-NPs, and the average size was 100±58.68 nm. All isolates were discovered to be of multidrug-resistant (MDR) type and fully susceptible to CST. The antibacterial activity of CTX and CIP was restored when combined with a sub-inhibitory level of ZnO-NPs (0.25 mg/L), and the highest activity was obtained at the concentrations of 32 µg/mL CTX and 8 µg/ mL CIP. Eventually, ZnO-NPs showed a synergistic effect on the antibacterial properties of CST against MDR Acinetobacter. Conclusions: This research indicated that the combination of ZnO-NPs with some common antibiotics can be considered as a novel strategy for reducing the spread of antibiotic-resistant bacteria.


2019 ◽  
Vol 9 (1-s) ◽  
pp. 196-200
Author(s):  
G Amalorpavamary ◽  
G Dineshkumar ◽  
K Jayaseelan

In recent times, plant-mediated synthesis of nanoparticles has garnered wide interest owing to its inherent features such as rapidity, simplicity, eco-friendliness and cheaper costs. For the first time, silver nanoparticles were successfully synthesized using Phyllanthus niruri leaf extract in the current investigation. The silver nanoparticles were characterized by UV–Vis spectrophotometer and the characteristic surface plasmon resonance peak was identified to be 423 nm. The morphology of the silver nanoparticles was characterized by scanning electron microscopy (SEM). The size of the silver nanoparticles was found to be 10-50 nm, with an average size 15 nm.  FTIR analysis was done to identify the functional groups responsible for the synthesis of the AgNPs. The antibacterial potential of synthesized AgNPs was compared with that of aqueous extracts of P.niruri by well diffusion method. The AgNPs at 50µl concentration significantly inhibited bacterial growth against A.hydrophila (16 ± 0.09 mm). Thus AgNPs showed broad spectrum antibacterial activity at lower concentration and may be a good alternative therapeutic approach in future. Keywords: Phyllanthus niruri, AgNps, Aeromonas hydrophila, Antibacterial Activity.


2021 ◽  
Vol 37 (3) ◽  
pp. 648-655
Author(s):  
Vinit Prakash ◽  
Harpreet Kaur ◽  
Anjana Kumari ◽  
Manoj Kumar ◽  
Sumeet Gupta ◽  
...  

Lagerstroemia speciosais commonly known as Banaba or Jarul which is used to get rid of various ailments such as fever, urinary infection, decongestion, diarrhoea, mouth ulcers, astringent, diabetes mellitus, kidney diseases, abdominal pains etc. The present work, describes the green synthesis of silver nanoparticles from ethanolic extract of fruits of L.speciosa (Ls-Ag NPs) and their analysis for antimicrobial activities. The characterisation of so obtained nanoparticles have been carried out with help of Field emission scanning electron microscopy (FESEM) and High-resolution transmission electron microscopy (HRTEM). Further, antimicrobial activities of ethanolic extract of fruits of L.speciosa(Ee-Ls), silver oxide (Ag2O), and Ls-Ag NPs have been examined by using well-diffusion method against two bacterial strains: Staphylococcus aureus (gram-positive) and Escherichia coli (gram-negative) and one fungal strain: Aspergillus niger.It has been observed that the biosynthesized Ls-Ag NPs possess much effective antimicrobial activity against selected strains as compared to Ee-Ls and Ag2O.


Author(s):  
Prakash Bhuyar ◽  
Mohd Hasbi Ab. Rahim ◽  
Sathyavathi Sundararaju ◽  
Rameshprabu Ramaraj ◽  
Gaanty Pragas Maniam ◽  
...  

Abstract Background Marine algae used as a food source for ocean life and range in color from red to green to brown grow along rocky shorelines around the world. The synthesis of silver nanoparticles by marine alga Padina sp. and its characterization were fulfilled by using UV-visible spectrophotometer, Fourier transform infrared spectroscopy, scanning electron microscopy and field emission scanning electron microscopy, and energy-dispersive X-ray spectroscopy. Results UV-visible absorption spectrum revealed that the formation of Ag nanoparticles was increased by the addition of marine algae and the spectral peak observed between a wavelength of ~ 420 nm and 445 nm. In addition, SEM and FESEM images examined the surface morphology and the size of the synthesized NPs was relatively uniform in size ~ 25–60 nm. Energy-dispersive X-ray spectroscopy analysis confirmed the purity of Ag NPs with atomic percentage of 48.34% Ag. The synthesized Ag NPs showed highly potent antibacterial activity. The Staphylococcus aureus and Pseudomonas aeruginosa were found to be more susceptible to silver nanoparticles by forming 15.17 ± 0.58 mm and 13.33 ± 0.76 mm of diameter of the inhibition zone, respectively. Conclusions The study suggested that marine alga Padina sp. could be an alternative source for the production of Ag nanoparticles and are efficient antimicrobial compounds against both gram-negative and gram-positive bacteria which can be a promising material against infectious bacteria.


Nanomaterials ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 592 ◽  
Author(s):  
Shi Lan ◽  
Yaning Lu ◽  
Chun Li ◽  
Shuang Zhao ◽  
Naren Liu ◽  
...  

In this contribution, we report for the first time on a new strategy for developing sesbania gum-supported hydrophilic fibers containing nanosilver using electrospinning (SG-Ag/PAN electrospun fibers), which gives the fibers superior antibacterial activity. Employing a series of advanced technologies—scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, UV–visible absorption spectroscopy, X-ray photoelectron spectroscopy, and contact angle testing—we characterized the as-synthesized SG-Ag/PAN electrospun fibers in terms of morphology, size, surface state, chemical composition, and hydrophilicity. By adjusting the synthesis conditions, in particular the feed ratio of sesbania gum (SG) and polyacrylonitrile (PAN) to Ag nanoparticles (NPs), we regulated the morphology and size of the as-electrospun fibers. The fibers’ antibacterial properties were examined using the colony-counting method with two model bacteria: Escherichia coli (a Gram-negative bacterium) and Staphylococcus aureus (a Gram-positive bacterium). Interestingly, compared to Ag/PAN and SG-PAN electrospun fibers, the final SG-Ag/PAN showed enhanced antibacterial activity towards both of the model bacteria due to the combination of antibacterial Ag NPs and hydrophilic SG, which enabled the fibers to have sufficient contact with the bacteria. We believe this strategy has great potential for applications in antibacterial-related fields.


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