Preparation and properties of silver nanocomposite fabrics with in situ-generated silver nano particles using red sanders powder extract as reducing agent

Nanocomposite cotton fabrics with in situ-generated silver nanoparticles (AgNPs) were prepared by using Pterocarpus santalinus (Red sanders) extract in water as a reducing agent. The formation of AgNPs was analyzed by scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy. The SEM analysis of nanocomposites showed the presence of spherical AgNPs with a size range of 71–90?nm. FTIR spectra showed the involvement of hydroxyl and methylene groups of cellulose matrix in reducing the silver salt into AgNPs in the presence of red sanders powder extract as reducing agent for the in situ generation of AgNPs. These nanocomposite fabrics exhibited good antibacterial activity against Gram positive and Gram negative bacteria.     

Nanocomposite polyester fabrics with in situ generated silver nanoparticles using tamarind leaf extract reducing agent

Using tamarind leaf extract as a reducing agent and various concentrated aq?AgNO₃ solutions as source, the silver nanoparticles (AgNPs) were in situ generated in polyester fabrics. The nanocomposite polyester fabrics were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction and antibacterial tests. The size of the generated AgNPs varied between 50 and 120?nm. The X-ray analysis indicated the generation of both AgNPs and AgO nanoparticles in the nanocomposite fabrics. The nanocomposite polyester fabrics exhibited excellent antibacterial activity against both the Gram negative and Gram positive bacteria and hence can be considered for making antibacterial textiles.     

Preparation and characterization of tamarind nut powder with in situ generated copper nanoparticles using one-step hydrothermal method

Tamarind nut powder (TNP) from kitchen waste of tamarind nuts was modified with in situ generated copper nanoparticles (CuNPs) using hydrothermal method. The modified TNP had spherical CuNPs with an average size of 84?nm. The thermal stability of the modified TNP was lower than that of the TNP due to the catalytic activity of the in situ generated CuNPs in lowering the thermal stability. Further, it exhibited significant antibacterial activity against both the Gram negative and Gram positive bacteria and hence can be used as low-cost filler to prepare antibacterial hybrid polymer nanocomposites for packaging and medical applications.     

Development and analysis of cellulose nanocomposite films with in situ generated silver nanoparticles using tamarind nut powder as a reducing agent

Cellulose/Tamarind nut powder (TNP)/Silver nanoparticles (AgNPs) nanocomposites were prepared by in situ generation of AgNPs using regeneration method, followed by solution casting method. In this, TNP was used as a reducing agent. These nanocomposites were characterized using FT-IR spectroscopy, XRD and SEM and studied their mechanical properties and antibacterial activity for medical and packing applications. The FT-IR spectral studies revealed the involvement of functional groups – Polyphenols, Flavonoids and –OH in the process of reducing the metal salts into metal nanoparticles. These nanocomposites showed good antibacterial activity against five bacteria. Improved mechanical properties with good antibacterial activities make these composites suitable for medical, food and packaging applications.     

In situ generation of silver nanoparticles in cellulose matrix using Azadirachta indica leaf extract as a reducing agent

In the present work, silver nanoparticles (AgNPs) were in situ generated in cellulose matrix using leaf extract of Azadirachta indica as a reducing agent. The cellulose/AgNP composite films prepared were characterized by FTIR, X-ray diffraction (XRD), scanning electron microscope, and antibacterial tests. The infrared spectra indicated the association of organic materials with silver nanoparticles to serve as capping agents. Scanning electron micrographs showed that synthesized silver nanoparticles were nearly uniform and spherical in shape with diameter in the range of 61–110?nm. XRD confirmed the formation of AgNPs and Ag–O nanoparticles. The nanocomposite films showed good antibacterial activity against Escherichia coli bacteria.     

Modification of agricultural waste tamarind fruit shell powder by in situ generation of silver nanoparticles for antibacterial filler applications

The tamarind fruit shell powder (TFSP) from agricultural waste was modified by in situ generation of silver nanoparticles (AgNPs) using the one-step hydrothermal method and characterized by SEM, EDX, FTIR spectral, XRD, and antibacterial tests. SEM analysis indicated the in situ generation of AgNPs with an average size of 90?nm. FTIR analysis proved no structural changes between unmodified and modified TFSP. XRD analysis indicated in situ generation of AgNPs in the modified TFSP. Further, the TFSP with in situ generated AgNPs inhibited the growth of bacteria and hence can be used as antibacterial low-cost filler in making biocomposites.     

Preparation and properties of low-cost cotton nanocomposite fabrics with in situ-generated copper nanoparticles by simple hydrothermal method

In this work, copper nanoparticles were in situ generated in cotton fabrics by simple hydrothermal method. These low-cost nanocomposite fabrics were characterized by scanning electron microscope (SEM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction, thermogravimetric analysis, and antibacterial tests. The presence of spherical nanoparticles was visualized by SEM analysis. FTIR spectra did not show any differences between the peak positions of cotton fabrics and their nanocomposites. The crystallinity of cotton nanocomposites was enhanced by the copper nanoparticles. The cotton nanocomposite fabrics exhibited good antibacterial activity against Escherichia coli bacteria and hence can be considered for medical applications such as wound dressing, surgical aprons, hospital bed materials, etc.     

Formulation and characterization of in situ generated copper nanoparticles reinforced cellulose composite films for potential antimicrobial applications

Cellulose was dissolved in aq.(LiOH + urea) solution pre-cooled to –12.5°C and the wet films were prepared using ethyl alcohol coagulation bath. The gel cellulose films were dipped in 10 wt.% Cassia alata leaf extract solution and allowed the extract to diffuse into them. The leaf extract infused wet cellulose films were dipped in different concentrated aq. copper sulphate solutions and allowed for in situ generation of copper nanoparticles (CuNPs) inside the matrix. The morphological, structural, antibacterial, thermal, and tensile properties of dried cellulose/CuNP composite films were carried out. The presence of CuNPs was established by EDX spectra and X-ray diffraction. The composite films displayed higher thermal stability than the matrix due to the presence of CuNPs. Cellulose/CuNP composite films possessed better tensile strength than the matrix. The composite films showed good antibacterial activity against E.coli bacteria. We conclude that good antibacterial activity and better tensile properties of the cellulose/CuNP composite films make them suitable for antibacterial wrapping and medical purposes.     

Effect of sunlight on the preparation and properties of cellulose/silver nanoparticle composite films by in situ method using Ocimum sanctum leaf extract as a reducing agent

Cellulose/silver nanoparticle composite films with in situ-generated silver nanoparticles (AgNPs) were prepared using Ocimum sanctum leaf extract as a reducing agent in the absence and presence of sunlight and were characterized by SEM, FTIR, XRD, and antibacterial tests. Sunlight hastened up the preparation of these composite films. The average size of the in situ-generated AgNPs was reduced by the sunlight. The antibacterial activity and other properties of the composites were enhanced by the sunlight. The cellulose/AgNP composite films with improved properties by sunlight can be considered for medical purpose as antibacterial dressing materials.     

Antibacterial cotton fabric with in situ generated silver nanoparticles by one-step hydrothermal method

The cotton fabrics were immersed in 1–5?mM aqueous silver nitrate solutions maintained at 80°C for 24?h to in situ generate silver nanoparticles. The presence of silver nanoparticles in the nanocomposite films was proved by microscopic observation. Fourier transform infrared spectra indicated the role of hydroxyl and carboxyl groups of cotton fabric in reducing the silver salt to nanosilver. The nanocomposite cotton fabrics showed good antibacterial activity against Gram-negative and Gram-positive bacteria. The antibacterial cotton fabrics can be considered for medical applications such as surgical aprons, wound cleaning, and dressing.     

Modification of natural fibers from Thespesia lampas plant by in situ generation of silver nanoparticles in single-step hydrothermal method

Ligno-cellulosic fibers have a great market and propose higher value addition and options to develop various products but they do not have inherent antimicrobial properties. In this study, a simple hydrothermal method was applied to build up antimicrobial properties to natural fibers by in situ-generating silver nanoparticles (AgNPs) in them. Herein, the ligno-cellulosic Thespesia lampas natural fibers were selected to develop antimicrobial activity using silver nitrate (AgNO₃) solution by hydrothermal method. The modified fibers were characterized by SEM, FTIR, XRD, TGA, and antibacterial activity tests. The modified fibers had spherical AgNPs with an average size of 95?nm. The thermal stability of the modified fibers was higher than that of the unmodified fibers. The modified fibers exhibited good antibacterial activity against both the Gram negative and Gram positive bacteria. These modified fibers can be considered as fillers in polymer matrices to make antibacterial composites.     

Antibacterial and antioxidant properties of phyto-synthesized silver nanoparticles using Lavandula stoechas extract

Due to environmentally friendly and cost- effective issues, biological methods for silver nanoparticles (AgNPs) synthesis are advantageous over chemical and physical ones. In this study, AgNPs synthesized using Lavandula stoechas extract as a reductant and its antioxidant capacity, antibacterial property and cytotoxicity effect were investigated. The phyto-synthesized AgNPs were characterized using various analyses such as transmission electron microscopy (TEM), scanning electron microscopy (SEM), x-ray diffraction (XRD) as well as Fourier transform infrared (FT-IR). The prepared nanoparticles were spherical on shape with the size about 20–50 nm. Antibacterial studies through agar disk diffusion method confirmed the antibacterial potential of phyto-synthesized AgNPs toward two clinical Staphylococus aureus and Pseudomonas aeruginosa bacteria, although MTT assay demonstrated that S. aureus (MIC = 125 μg/ml) was more susceptible to AgNPs than P. aeruginosa (MIC = 250 μg/ml). Moreover, the cytotoxicity assay of phyto-synthezied AgNPs showed a low cytotoxic effect on RAW264 cell line at 62.5 μg/ml as an effective concentration. Also the considerable antioxidant capacity of the AgNPs confirmed through DPPH assay. Great antibacterial and antioxidant properties along with biocompatibility make the suggested phyto-synthesized AgNPs a great candidate for different biomedical applications including wound healing.     

Green synthesis of silver nanoparticles using water extract of Salvia leriifolia: Antibacterial studies and applications as catalysts in the electrochemical detection of nitrite

Here, a green method is described for the biosynthesis of Ag nanoparticles (Ag NPs) using aqueous extracts of the leaf of Salvia leriifolia as reducing and stabilizing agent. Various techniques such as scanning electron microscopy (SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM) and X‐ray diffraction (XRD) were employed for the characterization of the structure and morphology of bio‐synthesized AgNPs. The results reveal that AgNPs synthesized with uniform spherical morphology and average diameters of 27 nm. The AgNPs as a green and efficient heterogeneous catalyst presented superior antibacterial activity. Direct electrochemistry studies of the synthesized AgNPs confirmed that nanoparticles retained their direct electrochemical activity. This is mainly attributed to the proper biosynthesis process, the large specific surface area and the good conductivity of the synthesized nanoparticles. Hence, the present synthesized AgNPs displayed good electrocatalytic activity to the reduction of nitrite ions. The proposed method is highly recommended as a novel platform for the development of electrochemical sensors which can further expand the applications of AgNPs. Antibacterial activity of the synthesized AgNPs was evaluated against nine microorganisms. AgNPs prevented the growth of all selected bacteria. The nanoparticles inhibited the growth of Pseudomonas aeruginosa, Klebsiella pneumonia, Staphylococcus coagulase, Acinetobacter baumannii, and Streptococcus pneumonia more than antibiotic of vancomycin, however, the ability of AgNPs against Echerishia coli and Serratia marcescens was less than the antibiotic. On the other hand AgNPs were active against Citrobacter frurdii, while the antibiotic was inactive.     

Preparation and properties of cellulose/silver nanoparticle composites with in situ-generated silver nanoparticles using Ocimum sanctum leaf extract

In the present work, silver nanoparticles were in situ-generated in cellulose matrix using Ocimum sanctum leaf extract as a reducing agent. Regenerated wet cellulose films were first immersed in O. sanctum leaf extract and then it was allowed to diffuse into the films. The leaf extract–diffused wet films were dipped in different concentrated aq.AgNO₃ solutions. The leaf extract inside the wet films reduced AgNO₃ into nanosilver. The dry composite films were black in color. Some of the nanoparticles were also formed outside the film in the solution. The nanoparticles were viewed by transmission electron microscopy and scanning electronic microscopy techniques. The composite films showed good antibacterial activity. The cellulose, matrix, and the composite films were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, and thermogravimetric analysis techniques. The tensile properties of the composite films were higher than those of the matrix. These biodegradable films can be used for packaging and medical purposes.     

Biomimetic synthesis of silver nanoparticles using Syzygium aromaticum (clove) extract: Catalytic and antimicrobial effects

In the current work, we followed a green chemistry route to prepare and characterize the silver nanoparticles (AgNPs) using Syzygium aromaticum (clove) extract at room temperature. Suitably, the clove extract acted as a reducing agent as well as a capping agent, and these reactions occurred rapidly. The formation of the AgNPs was confirmed by the observation of the distinct absorption peak at a wavelength of 418 nm using ultraviolet–visible (UV–Vis) spectroscopy, and a morphological study confirmed the uniform distribution of the optimally spherical nanoparticles. Fourier transform infrared spectroscopy (FTIR) results indicated the methoxy and allyl functional groups of eugenol of the clove extract to be responsible for the bioreduction of silver ions and for the stabilization of the resulting nanoparticles (flavonoids). We also found the AgNPs to be effective catalysts of the degradation of three pollutant organic dyes viz., 4‐nitrophenol, methylene blue and rhodamine B, in the presence of excess NaBH₄. The antibacterial and antifungal activities of the bio‐synthesized AgNPs were also explored. Overall, the results suggested the potential use of clove extract as a resource for the synthesis of AgNPs having a broad range of possible commercial and biomedical applications.     

Green synthesis and characterization of spherical copper nanoparticles as organometallic antibacterial agent

A facile and green route for the synthesis of copper nanoparticles (Cu NPs) has been achieved using green tea extract as a reducing, capping and stabilizing agent. UV–visible spectra gave surface plasmon resonance at 560 nm. The Cu NPs were characterized using various techniques. The size of the Cu NPs was about 20 nm. Antibacterial activity of biogenic Cu NPs were investigated against bacterial species Staphylococcus aureus , Bacillus subtilis , Pseudomonas aeruginosa and Escherichia coli and compared based on diameter of inhibition zone in disc diffusion assay and minimum inhibitory concentration and minimum bactericidal concentration of NPs dispersed in liquid cultures. The NPs showed better inhibitory activity against Gram‐positive bacteria (S. aureus and B. subtilis ) compared to Gram‐negative bacteria. Toxicity of the NPs was evaluated against animal cell line using MTT assay.     

Green synthesis and characterization of silver nanoparticles using Juniperus communis leaf extract: Catalytic activity in real-outdoor conditions and electrochemical properties

The present study investigates the green synthesis of stable silver nanoparticles using Juniperus communis leaf aqueous extract at room temperature. Synthesized silver nanoparticles (AgNPs) were characterized with different techniques such as UV–vis spectroscopy, Fourier transforms infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), Scanning electron microscopy (SEM-EDAX) and electrochemical method. Photocatalytic and anti-bacterial activities of synthesized AgNPs are evaluated based on the obtained result showed an efficient inhibition growth for gram negative P. Aeruginosa, E. Coli, and gram positive bacteria S.aureus. The AgNPs exhibited an excellent photocatalytic activity toward the degradation of methylene blue both indoor and outdoor, under sunlight, an efficiency of 95% was achieved. As an easy and environmentally friendly process, AgNPs based on Juniperus communis leaf extract could be applied for the degradation of pollutants and wastewater treatment.     

Biogenesis of copper nanoparticles using peel extract of Punica granatum and their antimicrobial activity against opportunistic pathogens

Copper nanoparticles (CuNPs) were biologically synthesized using peel extract of Punica granatum as reducing agent as well as capping agent. On treatment of aqueous solutions of CuSO₄·5H₂O with peel extract of P. granatum, stable CuNPs were formed. UV-Visible spectrophotometer analysis confirmed the formation of CuNPs. The synthesized nanoparticles were characterized with Fourier transform infrared spectroscopy, particles size analyzer and transmission electron microscopy (TEM). The electron microscopy analysis of CuNPs indicated that they ranged in size from 15 to 20?nm. The biologically synthesized CuNPs demonstrated high antibacterial activity against opportunistic pathogens, that is, Micrococcus luteus MTCC 1809, Pseudomonas aeruginosa MTCC 424, Salmonella enterica MTCC 1253 and Enterobactor aerogenes MTCC 2823 in vitro. Nanoparticles synthesized biologically using plant extracts have the potential to serve as possible ecofriendly alternatives to chemical and physical methods for biomedical applications and research.!     

Pistacia atlantica leaf extract mediated synthesis of silver nanoparticles and their antioxidant,cytotoxicity, and antibacterial effects under in vitro condition

Recently, researchers have investigated the therapeutical properties of metal nanoparticles especially silver nanoparticles in vitro and in vivo conditions. The aim of the experiment was green synthesis and chemical characterization of silver nanoparticles from aqueous extract of Pistacia atlantica leaf (Ag NPs) and evaluation of their cytotoxicity, antioxidant, and antibacterial effects under in vitro condition. Ag NPs were spherical with a size range of 40-60 nm and characterized using various analysis techniques including UV–Vis absorption spectroscopy to determine the presence of Ag NP in the solution. We studied functional groups of Pistacia atlantica extract in the reduction and capping process of Ag NP by FT-IR, crystallinity and FCC planes by XRD pattern, elemental analysis of the sample by EDS, and surface morphology, shapes, and size of Ag NPs by SEM, AFM, and TEM. Destroy initiation and termination temperatures of the Ag NPs were determined by TGA. DPPH free radical scavenging test was done to evaluate the antioxidant potentials, which indicated similar antioxidant potentials for Ag NPs and butylated hydroxytoluene. The synthesized Ag NPs had great cell viability dose-dependently and indicated this method was nontoxic. Agar diffusion tests were done to determine the antibacterial characteristic. Ag NPs revealed similar antibacterial property to the standard antibiotic. Also, Ag NPs prevented the growth of all bacteria at 1-7 μg/ml concentrations and removed them at 3-15 μg/ml concentrations. Finally, synthesized Ag NPs revealed non-cytotoxicity, antioxidant and antibacterial activities in a dose-depended manner.     

Green synthesis of iron (Fe) nanoparticles using Plumeria obtusa extract as a reducing and stabilizing agent: Antimicrobial,antioxidant and biocompatibility studies

In the current study, a green and facile route for the synthesis of iron nanoparticles (FeNPs) was adopted. The FeNPs were fabricated via a single step green route using aqueous leaves extract of Plumeria obtusa (P. obtusa) as a capping/reducing and stabilizing agents. The FeNPs were characterized by UV/Vis (Ultraviolet/Visible), FTIR (Fourier Transform Infra-Red spectroscopy), TEM (Transmission Electron Microscopy), SEM (Scanning Electron Microscopy) and XRD (X-Ray Diffraction) techniques. The FeNPs were of spheroidal shape with average size of 50 nm. The biosynthesized FeNPs were further evaluated for their biological activities like antimicrobial, antioxidant and biocompatibility. The FeNPs displayed auspicious antimicrobial activity against bacterial (E. coli, B. subtilis) and fungal strains (A. niger) and S. commune. The test performed against red blood cells (RBCs) lysis (1.22 ± 0.02%) and macrophage (31 ± 0.09%) showed biocompatible nature of FeNPs. In vitro cytotoxicity against AU565 (82.03 ± 0.08–23.65 ± 0.065%) and HeLa (88.61 ± 0.06–33.34 ± 0.06%) cell lines showed cell viability loss in dose dependent manner (FeNPs 25–100 μg/mL). The antioxidant activities values were determined through DPPH, TRPA, NO and H₂O₂ assays with values 70.23 ± 0.02%, 76.65 ± 0.02 μg AAE/mg, 74.43 ± 0.04% and 67.34 ± 0.03%, respectively. Based on the bioactivities, the green synthesized FeNPs have potential for therapeutic applications.