The Experts below are selected from a list of 4989 Experts worldwide ranked by ideXlab platform
Paulraj Kanmani - One of the best experts on this subject based on the ideXlab platform.
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physicochemical properties of gelatin Silver nanoparticle antimicrobial composite films
Food Chemistry, 2014Co-Authors: Paulraj Kanmani, Jongwhan RhimAbstract:Abstract Active nanocomposite films were prepared by blending aqueous solutions of gelatin with different concentrations of Silver nanoparticles (AgNPs) using a solvent casting method. Formation of Silver nanoparticles in the solution and films was confirmed with the surface plasmon resonance (SPR) band at 400–450 nm, measured by UV–vis absorption spectroscopy. The incorporation of AgNPs slightly affected the physical and mechanical properties of the films. Increase in the concentration of AgNPs resulted in a substantial decrease in water vapour permeability (WVP) and tensile strength (TS) of the gelatin films. Energy dispersive X-ray (EDX) spectroscopy and X-ray diffraction (XRD) analysis confirmed the presence of Elemental Silver and crystalline structure of the AgNPs in the gelatin film. Microscopic surface structure and thermal properties of the films were also examined by FE-SEM and thermogravimetric analysis. Gelatin/AgNPs nanocomposite films exhibited strong antibacterial activity against food-borne pathogens. Gelatin/AgNPs nanocomposite films are expected to have high potential as an active food packaging system to maintain food safety and to extend the shelf-life of packaged foods.
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physical mechanical and antimicrobial properties of gelatin based active nanocomposite films containing agnps and nanoclay
Food Hydrocolloids, 2014Co-Authors: Paulraj Kanmani, Jongwhan RhimAbstract:Abstract Antimicrobial bionanocomposite films were prepared with gelatin and Silver nanoparticles (AgNPs) and organoclay (Cloisite 30B) and their film properties were characterized. Transparency of nanocomposite films decreased, but UV barrier was greatly improved, which was more pronounced with AgNPs-included films. Hydrophobicity and water vapor barrier properties were also improved after formation of nanocomposite. The incorporation of AgNPs or clay into the gelatin film could affect the mechanical properties of films. Tensile strength (TS) increased significantly in the gelatin/clay and gelatin/AgNPs/clay films while decreased in the elongation at break (EB). EDX and XRD analysis were performed to examine the presence of Elemental Silver and crystallinity of AgNPs in the films. Microscopic surface structure analysis showed homogenous compact surface structure of the composite films. Interaction between the polymer and nanoparticles was tested by FT-IR analysis. The nanocomposite films, especially for gelatin/AgNPs/clay, exhibited strong antibacterial activity against food borne pathogens. These results suggested that the use of gelatin based nanocomposite films will help to compete and eliminate the bacterial invaders and to improve the shelf life and quality of food.
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synthesis and characterization of pullulan mediated Silver nanoparticles and its antimicrobial activities
Carbohydrate Polymers, 2013Co-Authors: Paulraj Kanmani, Seung Taik LimAbstract:Abstract Synthesis of Silver nanoparticles was achieved using pullulan as both a reducing and stabilizing agent. The effect of pullulan and Silver nitrate amounts on the synthesis of Silver nanoparticles (AgNPs) was investigated. The formation of nanoparticles was first screened by measuring the surface plasmon resonance peak at 420–430 nm using UV–vis spectroscopy. The morphology of the synthesized AgNPs was determined using TEM, which indicated that the AgNPs varied in shape and polydispersed with an average size of 2–30 nm. The presence of Elemental Silver and the crystalline structure of the AgNPs were confirmed by EDX and XRD analyses. The possible functional groups of pullulan responsible for the reduction and stabilization of AgNPs were evaluated using FT-IR. The pullulan-reduced AgNPs showed excellent antibacterial, antifungal, and antibiofilm activity against food and multidrug resistant bacterial and fungal pathogens. The results showed that pullulan could be used as a reducing as well as a capping agent for synthesizing AgNPs which had potent antimicrobial activity.
Valeria Harabagiu - One of the best experts on this subject based on the ideXlab platform.
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green synthesis of the Silver nanoparticles mediated by pullulan and 6 carboxypullulan
Carbohydrate Polymers, 2015Co-Authors: Sergiu Coseri, Alina Spatareanu, Liviu Sacarescu, Cristina Rimbu, Daniela Suteu, Stefan Spirk, Valeria HarabagiuAbstract:Abstract Unoxidized and carboxylated pullulan (obtained by pullulan oxidation using TEMPO–sodium hypochlorite–sodium bromide system) have been used as mediators for the Silver nanoparticles formation (AgNPs), under environment-friendly conditions: using aqueous solutions, room temperature and notably, by using both mediators as reducing and stabilizing agents. The formation of AgNPs was first screened by measuring the surface plasmon resonance peak in the range of 380–440 nm using UV–vis spectroscopy. The morphology of the synthesized Silver nanoparticles was determined by TEM, which indicated that the AgNPs differ on shape and thickness of the polymer shell by varying the Silver nitrate concentration, different size and shape of AgNPs was achieved. The presence of Elemental Silver and the crystalline structure of the AgNPs were confirmed by EDX and XRD analyses. Moreover, the possible functional groups of pullulan (oxidized pullulan) responsible for the reduction and stabilization of AgNPs were evaluated using FT-IR. The results showed that both, pullulan and 6-carboxypullulan could be successfully used as reducing as well as capping agents for the AgNPs synthesis which shows potential antimicrobial activity against Gram positive and Gram negative bacteria.
Gun-do Kim - One of the best experts on this subject based on the ideXlab platform.
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doxycycline hyclate mediated Silver Silver chloride nanoparticles and their antibacterial activity
journal of nanostructure in chemistry, 2019Co-Authors: Maheshkumar Prakash Patil, Lei Lottice Anne Piad, Enkhnaran Bayaraa, Paul Subedi, Naresh Hiralal Tarte, Gun-do KimAbstract:In the present work, we used doxycycline hyclate (DX) and tetramethylguanidine (TMG) for the synthesis of Silver–Silver chloride nanoparticles (DX-Ag–AgCl NPs) as a simple method for the production of nanoparticles (NPs). A new synthesis method for DX-Ag–AgCl NPs in aqueous medium, using the DX and TMG as a reducing and stabilizing agent, is reported. DX-Ag–AgCl NPs were characterized by transmission electron microscopy. The Elemental composition and the crystalline nature of synthesized nanoparticles were determined by energy-dispersive X-ray (EDX) spectroscopy and X-ray diffraction (XRD) analysis, respectively. From EDX, it is confirmed that synthesized NPs contain Elemental Silver and chloride, and their crystalline nature was confirmed by XRD. The Fourier transform infra-red spectra showed the DX present in surface of DX-Ag–AgCl NPs. Synthesized NPs analyzed for antibacterial activity by agar well method against Gram-positive and Gram-negative pathogens. Synthesized DX-Ag–AgCl NPs were spherical shaped and in the range of 10–40 nm of size was observed from TEM images. In the crystalline nature, XRD peaks indicate the presence of Silver and Silver chloride in produced NPs. Synthesized NPs show potential antibacterial activity on Bacillus cereus KCCM 11773, Bacillus subtilis KCCM 11316, Staphylococcus aureus KCCM 40050, Escherichia coli KCCM 11234, Klebsiella pneumoniae KCCM 11418, and Proteus vulgaris KCCM 40211.
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Doxycycline hyclate mediated Silver–Silver chloride nanoparticles and their antibacterial activity
SpringerOpen, 2019Co-Authors: Maheshkumar Prakash Patil, Lei Lottice Anne Piad, Enkhnaran Bayaraa, Paul Subedi, Naresh Hiralal Tarte, Gun-do KimAbstract:Abstract In the present work, we used doxycycline hyclate (DX) and tetramethylguanidine (TMG) for the synthesis of Silver–Silver chloride nanoparticles (DX-Ag–AgCl NPs) as a simple method for the production of nanoparticles (NPs). A new synthesis method for DX-Ag–AgCl NPs in aqueous medium, using the DX and TMG as a reducing and stabilizing agent, is reported. DX-Ag–AgCl NPs were characterized by transmission electron microscopy. The Elemental composition and the crystalline nature of synthesized nanoparticles were determined by energy-dispersive X-ray (EDX) spectroscopy and X-ray diffraction (XRD) analysis, respectively. From EDX, it is confirmed that synthesized NPs contain Elemental Silver and chloride, and their crystalline nature was confirmed by XRD. The Fourier transform infra-red spectra showed the DX present in surface of DX-Ag–AgCl NPs. Synthesized NPs analyzed for antibacterial activity by agar well method against Gram-positive and Gram-negative pathogens. Synthesized DX-Ag–AgCl NPs were spherical shaped and in the range of 10–40 nm of size was observed from TEM images. In the crystalline nature, XRD peaks indicate the presence of Silver and Silver chloride in produced NPs. Synthesized NPs show potential antibacterial activity on Bacillus cereus KCCM 11773, Bacillus subtilis KCCM 11316, Staphylococcus aureus KCCM 40050, Escherichia coli KCCM 11234, Klebsiella pneumoniae KCCM 11418, and Proteus vulgaris KCCM 40211
Stefan Spirk - One of the best experts on this subject based on the ideXlab platform.
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green synthesis of the Silver nanoparticles mediated by pullulan and 6 carboxypullulan
Carbohydrate Polymers, 2015Co-Authors: Sergiu Coseri, Alina Spatareanu, Liviu Sacarescu, Cristina Rimbu, Daniela Suteu, Stefan Spirk, Valeria HarabagiuAbstract:Abstract Unoxidized and carboxylated pullulan (obtained by pullulan oxidation using TEMPO–sodium hypochlorite–sodium bromide system) have been used as mediators for the Silver nanoparticles formation (AgNPs), under environment-friendly conditions: using aqueous solutions, room temperature and notably, by using both mediators as reducing and stabilizing agents. The formation of AgNPs was first screened by measuring the surface plasmon resonance peak in the range of 380–440 nm using UV–vis spectroscopy. The morphology of the synthesized Silver nanoparticles was determined by TEM, which indicated that the AgNPs differ on shape and thickness of the polymer shell by varying the Silver nitrate concentration, different size and shape of AgNPs was achieved. The presence of Elemental Silver and the crystalline structure of the AgNPs were confirmed by EDX and XRD analyses. Moreover, the possible functional groups of pullulan (oxidized pullulan) responsible for the reduction and stabilization of AgNPs were evaluated using FT-IR. The results showed that both, pullulan and 6-carboxypullulan could be successfully used as reducing as well as capping agents for the AgNPs synthesis which shows potential antimicrobial activity against Gram positive and Gram negative bacteria.
P Venkatachalam - One of the best experts on this subject based on the ideXlab platform.
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caesalpinia coriaria leaf extracts mediated biosynthesis of metallic Silver nanoparticles and their antibacterial activity against clinically isolated pathogens
Industrial Crops and Products, 2014Co-Authors: K Jeeva, M Thiyagaraja, V Elangova, N P Geetha, P VenkatachalamAbstract:Abstract A rapid method for synthesis of Silver nanoparticles using the leaf extracts of Caesalpinia coriaria that has high level of tannin contents is reported. For leaf extracts preparation, two methods were adopted and compared with their extracellular synthesis of metallic Silver nanoparticles. Stable Silver nanoparticles produced by treating an aqueous solution of AgNO3 (5 mM) with the leaf extracts as reducing agent of Ag+ to Ag0. The formation of the Silver nanoparticles (AgNPs) in the reaction mixture was determined using the surface plasmon resonance band shown in UV–vis spectroscopy. To identify the active biomolecules responsible for the reduction of Ag+ ion and the stabilization of AgNPs synthesized the functional group available in C. coriaria leaf extracts (CCLE) was studied by Fourier transmission infrared (FT-IR) spectroscopy. The X-ray diffraction (XRD) analysis showed the crystalline structure of metallic Silver ions. The energy dispersive X-ray spectroscopy (EDX) analysis of AgNPs was confirmed the presence of pure Elemental Silver ion with no other impurity peaks. The morphology and topography of the AgNPs were determined using field emission scanning electron microscopy (FESEM). The size of the Silver nanoparticles was differed by the kind of leaf extracts used for synthesis. The morphology of the AgNPs synthesized using boiled leaf extracts was found to be triangle shape with diameter range from 40 nm to 52 nm whereas in the case centrifuged leaf extracts, three shapes viz., triangle, hexagonal and spherical were noticed with an average size between 78 nm and 98 nm. Furthermore the synthesized AgNPs were found to show potential antimicrobial activity against multidrug resistant Gram-positive (Escherichia coli and Pseudomonas aeruginosa) and Gram-negative (Klebsiella pneumoniae, and Staphylococcus aureus) clinically isolated human pathogens. The present results clearly indicated that the CCLE is a good nontoxic source for extracellular synthesis of AgNPs in eco-friendly way as compared to other methods. Thus C. coriaria leaf extracts provide a potential source for development of commercially important industrial products including cosmetics and nanomedicines by tagging nanoparticels with tannins in the future.