Effect of Plasmid DNA Dimension Evolution on the Size of Ag Nanoparticles during Photoirradiation

2016 ◽  
Vol 847 ◽  
pp. 194-199
Author(s):  
Jin Dan Zhang ◽  
Mei Yu ◽  
Jian Hua Liu ◽  
Song Mei Li ◽  
Yan Bing Meng
Keyword(s):  
Linear Relationship ◽  
Plasmid Dna ◽  
Ag Nanoparticles ◽  
Synthesis Process ◽  
Ag Nps ◽  
Base Pairs ◽  
Ultraviolet C ◽  
Metallic Nanomaterials ◽  
Ft Ir ◽  
Induce Condition

Under the photoirradiation, DNA works as both template and reducing agent to drive the formation of metallic nanomaterials. In this study the plasmid DNA with different base pairs was applied as biotemplate to synthesize Ag nanoparticles (NPs) by using photoirradiation approach. The evolution of DNA dimension changed during the synthesis process, and their effect on the morphology of the synthesized Ag NPs was studied by UV-Vis spectra, FT-IR spectra, Raman spectra, AFM, and TEM. It is found that the plasmid DNA shrinked twice during the synthesis, the first time happened when the Ag (I) cations neutralized the negative charge along the DNA chain, and the second time happened when plasmid DNA reduced Ag (I) induced by the ultraviolet C (254 nm) irradiation. The size of the synthesized Ag NPs showed approximately linear relationship with the dimension of plasmid DNA scaffolds under this photo-induce condition. The compaction degree of the plasmid DNA during the Ag formation was shown by the slope of the linear relationship.

scholarly journals Ag Nanoparticles Sensitized In2O3 Nanograin for the Ultrasensitive HCHO Detection at Room Temperature

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Shiqiang Zhou ◽  
Mingpeng Chen ◽  
Qingjie Lu ◽  
Yumin Zhang ◽  
Jin Zhang ◽  
...  
Keyword(s):  
Indoor Air ◽  
Ag Nanoparticles ◽  
Room Temperature ◽  
Unsolved Problem ◽  
Air Pollutant ◽  
Ag Nps ◽  
Performance Targets ◽  
Fabrication Cost ◽  
Low Concentrations ◽  
Stringent Performance

AbstractFormaldehyde (HCHO) is the main source of indoor air pollutant. HCHO sensors are therefore of paramount importance for timely detection in daily life. However, existing sensors do not meet the stringent performance targets, while deactivation due to sensing detection at room temperature, for example, at extremely low concentration of formaldehyde (especially lower than 0.08 ppm), is a widely unsolved problem. Herein, we present the Ag nanoparticles (Ag NPs) sensitized dispersed In2O3 nanograin via a low-fabrication-cost hydrothermal strategy, where the Ag NPs reduces the apparent activation energy for HCHO transporting into and out of the In2O3 nanoparticles, while low concentrations detection at low working temperature is realized. The pristine In2O3 exhibits a sluggish response (Ra/Rg = 4.14 to 10 ppm) with incomplete recovery to HCHO gas. After Ag functionalization, the 5%Ag-In2O3 sensor shows a dramatically enhanced response (135) with a short response time (102 s) and recovery time (157 s) to 1 ppm HCHO gas at 30 °C, which benefits from the Ag NPs that electronically and chemically sensitize the crystal In2O3 nanograin, greatly enhancing the selectivity and sensitivity.

scholarly journals Green approach in gold, silver and selenium nanoparticles using coffee bean extract

2020 ◽  
Vol 5 (1) ◽  
pp. 761-767
Author(s):  
Reiyhaneh Abbasian ◽  
Hoda Jafarizadeh-Malmiri
Keyword(s):  
Spherical Shape ◽  
Coffee Bean ◽  
Hydrothermal Conditions ◽  
Ag Nps ◽  
Au Nps ◽  
Stabilizing Agents ◽  
E Coli ◽  
Green Approach ◽  
Gold Silver ◽  
Ft Ir

AbstractGreen fabrication of metal nanoparticles (NPs), using natural reducing and stabilizing agents existed in plants and their derivatives, due to their unique properties, has gained more attention. The present study focuses on the synthesis of gold (Au), silver (Ag) and selenium (Se) NPs using coffee bean extract under hydrothermal conditions (1.5 atm and 121°C, for 15 min). Coffee bean extract obtained in 2 h processing using Clevenger apparatus and Fourier transform-infrared (FT-IR) spectroscopy indicated five highlighted peaks, namely, hydroxyl, amide, aromatic, alkane and ring groups. Dynamic light scattering analysis revealed that among three different NPs formed, fabricated Ag NPs had small particle size (153 nm) and high zeta potential value (16.8 mV). However, synthesized Au NPs had minimum polydispersity index (0.312). Results also indicated that fabricated Au, Se and Ag NPs had low antioxidant activity with values of 9.1, 8.9 and 8.7%, respectively. Morphological and antibacterial activity assessments, demonstrated that synthesized Ag, Au and Se NPs had spherical shape and high bactericidal activity against E. coli and S. aurous. Obtained results indicated that the synthesized NPs, can be utilized in various areas.

Repair of heteroduplex plasmid DNA after transformation into Saccharomyces cerevisiae

1986 ◽  
Vol 6 (10) ◽  
pp. 3401-3409
Author(s):  
D K Bishop ◽  
R D Kolodner
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Plasmid Dna ◽  
Base Pair ◽  
Base Pairs ◽  
Plasmid Dnas ◽  
Repair Efficiency ◽  
Single Insertion ◽  
Base Pair Insertion

Purified heteroduplex plasmid DNAs containing 8- or 12-base-pair insertion mismatches or AC or CT substitution mismatches were used to transform Saccharomyces cerevisiae. Two insertion mismatches, separated by 943 base pairs, were repaired independently of each other at least 55% of the time. This suggested that repair tracts were frequently shorter than 1 kilobase. The two insertion mismatches were repaired with different efficiencies. Comparison of the repair efficiency of one mismatched site with or without an adjacent mismatch suggests that mismatches promote their own repair and can influence the repair of neighboring mismatches. When two different plasmids containing single-insertion mismatches were transformed into S. cerevisiae cells, a slight preference towards insertion was detected among repair products of one of the two plasmids, while no repair preference was detected among transformants with the second plasmid.

scholarly journals Structural and Optical Analysis of Ag Nanoparticles assisted Vertically Aligned TiO2 Nanowires based photoanode for Dye-sensitized Solar Cells Application

2021 ◽  
Author(s):  
Biraj Shougaijam ◽  
Salam Surjit Singh
Keyword(s):  
Solar Cells ◽  
Ag Nanoparticles ◽  
Dye Sensitized Solar Cells ◽  
Visible Region ◽  
Ag Nps ◽  
Dye Sensitized ◽  
Vertically Aligned ◽  
Glad Technique ◽  
Sensitized Solar Cells ◽  
Pet Substrate

Abstract In this work, vertically aligned TiO 2 -Nanowires (TiO 2 -NWs) and Ag Nanoparticles assisted TiO 2 Nanowires (TAT-NWs) were deposited on glass and flexible PET substrates using the Glancing Angle Deposition (GLAD) technique. The morphology and structural analysis of the samples manifest the successful deposition of vertically aligned TiO 2 -NWs and TAT-NWs. The HR-TEM image of TiO 2 -NWs shows the polycrystalline nature. Further, the XRD result confirms the polycrystalline nature of both the TiO 2 -NWs and TAT-NWs samples. Besides, the HR-TEM image confirms the presence of small crystal grains of Ag Nanoparticles (Ag-NPs) at the mid of the annealed TAT-NWs. It is evident from the Selective Area Electron Diffraction (SAED) analysis of the TiO 2 -NWs and annealed TAT-NWs that the crystallinity of TiO 2 present in the annealed TAT-NWs improves after annealing. The absorption spectrum analysis of TAT-NWs deposited on glass substrate shows enhance absorption peak in the visible region with a maximum peak at ~463 nm wavelength compare to the TiO 2 -NWs, which may be attributed to the Surface Plasmon Resonance (SPR) effect of Ag-NPs. Further, it is interesting to observe that the TAT-NWs deposited on PET substrate show further absorption enhancement in the UV and visible region. In addition, the Photoluminescence analysis reveals that the bandgap of the TiO 2 -NWs is ~3.12 eV, which supports the bandgap extracted from the Tauc plot. Therefore, the proposed method of fabricating TAT-NWs on glass and flexible ITO coated PET substrate using the GLAD technique may be applicable for developing novel photoanode for Dye-sensitized Solar Cells (DSSCs) and other optoelectronic applications.

scholarly journals Hydroxyapatite-ciprofloxacin delivery system: Synthesis, characterisation and antibacterial activity

2018 ◽  
Vol 68 (2) ◽  
pp. 129-144 ◽  
Author(s):  
Maria-Viorica Ciocilteu ◽  
Andreea Gabriela Mocanu ◽  
Adriana Mocanu ◽  
Catalin Ducu ◽  
Oana Elena Nicolaescu ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Chemical Precipitation ◽  
Precipitation Method ◽  
Synthesis Process ◽  
Diffusion Controlled ◽  
Ft Ir ◽  
Inhibition Zones ◽  
Bacterial Growth Inhibition ◽  
Local Release

Abstract The main objective of this study was to synthesize hydroxyapatite-ciprofloxacin composites using a chemical precipitation method and to evaluate the properties and in vitro release profile of the drug from the hydroxyapatite-ciprofloxacin composites. Composite characterization was achieved by FT-IR, XRD and DLS. Ciprofloxacin determination was accomplished by HPLC, resulting in good incorporation efficiency of the drug (18.13 %). The in vitro release study (Higuchi model C = K t1/2 and Ritger-Peppas model, C = K t0.6) showed a diffusion-controlled mechanism. The antibacterial activity showed that the bacterial growth inhibition zones were approximately equal for the synthesis composites and for the mechanical mixture on the Staphylococcus aureus germ. The use of hydroxyapatite, which is a biocompatible, bioactive and osteoconductive material, with ciprofloxacin, which has good antibacterial activity in this composite, makes it suitable for the development of bone grafts. Furthermore, the synthesis process allows a slow local release of the drug.

scholarly journals Nanosized MoO3 as a reusable heterogeneous catalyst for the synthesis of 2,6-bis(benzylidene)cyclohexanones

2015 ◽  
Vol 33 (1) ◽  
pp. 163-168 ◽  
Author(s):  
Nitin R. Dighore ◽  
Priyanka L. Anandgaonker ◽  
Suresh T. Gaikwad ◽  
Anjali S. Rajbhoj
Keyword(s):  
Heterogeneous Catalyst ◽  
Product Yield ◽  
Synthesis Process ◽  
X Ray Diffraction ◽  
Structure Directing Agent ◽  
Vis Spectroscopy ◽  
Solvent Formation ◽  
Ft Ir ◽  
Work Up ◽  
Ft Ir Spectroscopy

AbstractCrystalline MoO3 nanoparticles were obtained by electrochemical synthesis process using tetrapropylammonium bromide as a stabilizer and structure-directing agent in ACN:THF(4:1) solvent. Formation of MoO3 nanoparticles took place at a constant supply current of 14 mA/cm2. These synthesized MoO3 nanoparticles were characterized by UV-Vis spectroscopy, FT-IR spectroscopy, powder X-ray diffraction (XRD), scanning electron microscopy (SEM). So prepared MoO3 nanoparticles were used as a heterogeneous catalyst for the synthesis of 2,6-bis(benzylidene)cyclohexanone derivatives. This protocol offers several advantages, such as simple work-up procedure, recyclability of the catalyst, excellent product yield in a short reaction time and purification of products with a non-chromatographic method.

An approach for the efficient immobilization of 79Se using Fe-OOH modified GMZ bentonite

2020 ◽  
Vol 108 (2) ◽  
pp. 113-126
Author(s):  
Junqiang Yang ◽  
Keliang Shi ◽  
Xuejie Sun ◽  
Xiaoqing Gao ◽  
Peng Zhang ◽  
...  
Keyword(s):  
Low Cost ◽  
High Mobility ◽  
Synthesis Process ◽  
Gmz Bentonite ◽  
Filling Material ◽  
Xps Spectra ◽  
Ft Ir ◽  
High Level ◽  
Critical Consideration ◽  
Formation Of Complexes

AbstractBecause of high mobility, the immobilization of long-lived fission product 79Se (often existed as 79Se(IV) and 79Se(VI) anions) is a critical consideration in the repository of high-level radioactive waste. In this work, a Fe-OOH modified bentonite (Fe-OOH-bent) was synthesized as a potential filling material in the repository site for effective adsorption and present the migration of different species of 79Se. The adsorbent was characterized using FT-IR, XRD, XFS, zeta potential and BET to clarify its physical properties, compositions and structures. A good thermal and radiation stabilities of Fe-OOH-bent was confirmed by its stable uptake ratio for Se(IV) and Se(VI) compared to original samples. The batch experimental results show that Se(IV) and Se(VI) can be efficiently removed from aqueous by Fe-OOH-bent within 60 min with maximum adsorption capacities of 68.45 mg/g for Se(IV) and 40.47 mg/g for Se(VI) in the optimal conditions, indicating its high potential application in consideration of its simple synthesis process, low cost and high adsorption capacity in view of immobilization of 79Se. The surface species and variation of oxide state of Fe as well as Se(IV) and Se(VI) onto Fe-OOH-bent were investigated by XPS analysis. The values of relative area of Se(IV)–O and Se(VI)–O in XPS spectra followed the same tendency as their adsorption ratio with the variation of system pH, suggesting that the formation of complexes between selenium species and Fe-OOH-bent surface.

scholarly journals Biosynthetic potential assessment of four food pathogenic bacteria in hydrothermally silver nanoparticles fabrication

2019 ◽  
Vol 8 (1) ◽  
pp. 629-634 ◽  
Author(s):  
Amir Rahimirad ◽  
Afshin Javadi ◽  
Hamid Mirzaei ◽  
Navideh Anarjan ◽  
Hoda Jafarizadeh-Malmiri
Keyword(s):  
Particle Size ◽  
Silver Nanoparticles ◽  
Zeta Potential ◽  
Pathogenic Bacteria ◽  
Heating Time ◽  
Synthesis Process ◽  
Ag Nps ◽  
Physico Chemical ◽  
Minimum Particle Size ◽  
Particle Size Analyzer

Abstract Silver nanoparticles (Ag NPs) were synthesized using four pathogenic bacterial extracts namely, Bacillus cereus, E. coli, Staphylococcus aureus and Salmonella entericasubsp.enterica. Synthesis process were hydrothermally accelerated using temperature, pressure and heating time of 121°C, 1.5 bar ad 15 min. Physico- chemical characteristics of the fabricated Ag NPs, including, particle size, polydispersity index (PDI), zeta potential, broad emission peak (λmax) and concentration were evaluated using UV-Vis spectrophotometer and dynamic light scattering (DLS) particle size analyzer. Furthermore, main existed functional groups in the provided bacterial extracts were recognized using Fourier transform infrared spectroscopy. The obtained results revealed that two main peaks were detected around 3453 and 1636.5 cm-1, for all bacterial extracts, were interrelated to the stretching vibrations of hydroxyl and amide groups which those had key roles in the reduction of ions and stabilizing of the formed Ag NPs. The results also indicated that, Ag NPs with much desirable characteristics, including minimum particle size (25.62 nm) and PDI (0.381), and maximum zeta potential (-29.5 mV) were synthesized using S. e. subsp. enterica extract. λmax, absorbance and concentration values for the fabricated Ag NPs with this bacterial extract were 400 nm, 0.202% a.u. and 5.87 ppm.

Molecular sieving property adjusted by the encapsulation of Ag nanoparticles into ZnO@ZIF-71 nanorod arrays

2019 ◽  
Vol 55 (74) ◽  
pp. 11045-11048 ◽  
Author(s):  
Tingting Zhou ◽  
Ziyu Qin ◽  
Xiaoxia Wang ◽  
Congyi Wu ◽  
Xing Tang ◽  
...  
Keyword(s):  
Ag Nanoparticles ◽  
Nanorod Arrays ◽  
Ag Nps ◽  
Molecular Sieving

Ag NPs are encapsulated into ZIF-71 serving as an adjustable molecular sieving layer to hydrogen and acetone.

scholarly journals Synthesis and biological characterization of silver nanoparticles derived from the cyanobacterium Oscillatoria limnetica

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ragaa A. Hamouda ◽  
Mervat H. Hussein ◽  
Rasha A. Abo-elmagd ◽  
Salwa S. Bawazir
Keyword(s):  
Silver Nanoparticles ◽  
Cell Line ◽  
Fourier Transforms ◽  
Human Colon ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Ag Nps ◽  
Human Colon Cancer ◽  
Visible Absorption ◽  
Ft Ir

Abstract Using aqueous cyanobacterial extracts in the synthesis of silver nanoparticle is looked as green, ecofriendly, low priced biotechnology that gives advancement over both chemical and physical methods. In the current study, an aqueous extract of Oscillatoria limnetica fresh biomass was used for the green synthesis of Ag-NPs, since O. limnetica extract plays a dual part in both reducing and stabilizing Oscillatoria-silver nanoparticles (O-AgNPs). The UV-Visible absorption spectrum, Fourier transforms infrared (FT-IR), transmission electron microscopy (TEM) and scanning electron microscope (SEM) were achieved for confirming and characterizing the biosynthesized O-AgNPs. TEM images detected the quasi-spherical Ag-NPs shape with diverse size ranged within 3.30–17.97 nm. FT-IR analysis demonstrated the presence of free amino groups in addition to sulfur containing amino acid derivatives acting as stabilizing agents as well as the presence of either sulfur or phosphorus functional groups which possibly attaches silver. In this study, synthesized Ag-NPs exhibited strong antibacterial activity against multidrug-resistant bacteria (Escherichia coli and Bacillus cereus) as well as cytotoxic effects against both human breast (MCF-7) cell line giving IC50 (6.147 µg/ml) and human colon cancer (HCT-116) cell line giving IC50 (5.369 µg/ml). Hemolytic activity of Ag-NPs was investigated and confirmed as being non- toxic to human RBCs in low concentrations.

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