scholarly journals Effect of Ag NPs on the radiant absorption of photocatalyst film

AIMS Energy ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 830-841
Author(s):  
Jiayu Li ◽  
◽  
Jiewen Guo
Keyword(s):  
Ag Nps

scholarly journals Single-Step Green Synthesis of Highly Concentrated and Stable Colloidal Dispersion of Core-Shell Silver Nanoparticles and Their Antimicrobial and Ultra-High Catalytic Properties

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1007
Author(s):  
Azam Ali ◽  
Mariyam Sattar ◽  
Fiaz Hussain ◽  
Muhammad Humble Khalid Tareen ◽  
Jiri Militky ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Tannic Acid ◽  
Rate Constant ◽  
Catalytic Properties ◽  
Colloidal Dispersion ◽  
Alkaline Condition ◽  
Core Shell ◽  
Average Particle ◽  
Ag Nps

The versatile one-pot green synthesis of a highly concentrated and stable colloidal dispersion of silver nanoparticles (Ag NPs) was carried out using the self-assembled tannic acid without using any other hazardous chemicals. Tannic acid (Plant-based polyphenol) was used as a reducing and stabilizing agent for silver nitrate in a mild alkaline condition. The synthesized Ag NPs were characterized for their concentration, capping, size distribution, and shape. The experimental results confirmed the successful synthesis of nearly spherical and highly concentrated (2281 ppm) Ag NPs, capped with poly-tannic acid (Ag NPs-PTA). The average particle size of Ag NPs-PTA was found to be 9.90 ± 1.60 nm. The colloidal dispersion of synthesized nanoparticles was observed to be stable for more than 15 months in the ambient environment (25 °C, 65% relative humidity). The synthesized AgNPs-PTA showed an effective antimicrobial activity against Staphylococcus Aureus (ZOI 3.0 mM) and Escherichia coli (ZOI 3.5 mM). Ag NPs-PTA also exhibited enhanced catalytic properties. It reduces 4-nitrophenol into 4-aminophenol in the presence of NaBH4 with a normalized rate constant (Knor = K/m) of 615.04 mL·s−1·mg−1. For comparison, bare Ag NPs show catalytic activity with a normalized rate constant of 139.78 mL·s−1·mg−1. Furthermore, AgNPs-PTA were stable for more than 15 months under ambient conditions. The ultra-high catalytic and good antimicrobial properties can be attributed to the fine size and good aqueous stability of Ag NPs-PTA. The unique core-shell structure and ease of synthesis render the synthesized nanoparticles superior to others, with potential for large-scale applications, especially in the field of catalysis and medical.

scholarly journals Antibacterial activity of royal jelly-mediated green synthesized silver nanoparticles

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Susanna Gevorgyan ◽  
Robin Schubert ◽  
Mkrtich Yeranosyan ◽  
Lilit Gabrielyan ◽  
Armen Trchounian ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Green Synthesis ◽  
Royal Jelly ◽  
Fluorescence Emission ◽  
Spherical Particles ◽  
Ag Nps ◽  
Gram Negative ◽  
Green Synthesized Silver Nanoparticles ◽  
Higher Sensitivity

AbstractThe application of green synthesis in nanotechnology is growing day by day. It’s a safe and eco-friendly alternative to conventional methods. The current research aimed to study raw royal jelly’s potential in the green synthesis of silver nanoparticles and their antibacterial activity. Royal jelly served as a reducing and oxidizing agent in the green synthesis technology of colloidal silver nanoparticles. The UV–Vis maximum absorption at ~ 430 nm and fluorescence emission peaks at ~ 487 nm confirmed the presence of Ag NPs. Morphology and structural properties of Ag NPs and the effect of ultrasound studies revealed: (i) the formation of polydispersed and spherical particles with different sizes; (ii) size reduction and homogeneity increase by ultrasound treatment. Antibacterial activity of different concentrations of green synthesized Ag NPs has been assessed on Gram-negative S. typhimurium and Gram-positive S. aureus, revealing higher sensitivity on Gram-negative bacteria.

scholarly journals Growth and yield performances of rice (Oryza sativa var. nerica) after exposure to biosynthesized nanoparticles

2021 ◽  
Vol 45 (1) ◽  
Author(s):  
B. Ikhajiagbe ◽  
F. A. Igiebor ◽  
M. C. Ogwu
Keyword(s):  
Oryza Sativa ◽  
Moringa Oleifera ◽  
Carica Papaya ◽  
Heavy Metal Contamination ◽  
Physiological Stress ◽  
Standard Procedure ◽  
Growth And Yield ◽  
Vernonia Amygdalina ◽  
Ag Nps ◽  
Viable Seeds

Abstract Background Rice (Oryza sativa L.) is a common staple food in Nigeria. However, cultivation is impaired by heavy metal contamination, particularly iron (Fe). This study aimed to investigate the impacts of biosynthesized nanoparticles (NPs) in enhancing the growth and yield components of rice sown in ferruginous soil. Viable seeds of O. sativa var. nerica were sown in ferruginous and non-ferruginous soils. After four weeks, the plants were exposed to foliar sprays of biosynthesized NPs from silver nitrate, using extracts of leaves of Carica papaya, Vernonia amygdalina, Moringa oleifera, and Azadirachta indica; and the flowers of Hibiscus sabderiffa, following standard procedure. The originally prepared stock solution was diluted to give 5, 15, and 30% concentrations of each synthesized NP. Results Results showed that soil ferrugenicity impeded the growth and yield of rice. Azadirachta-synthesized NPs was better enhanced in the ferruginous soils, which might be due to Fe interaction and activities. Moreover, there was increased antioxidant activity in the ferruginous rice compared to the non-ferruginous rice, thus it is evidence that ferrugenicity is a major source of physiological stress for the rice plant. Conclusion The study provided evidence that Ag-NPs can enhance plant yield by huge proportions in ferruginous soil, a condition (ferrugenicity) that was hitherto inimical to yield disposition of rice.

scholarly journals Green synthesized silver and copper nanoparticles induced changes in biomass parameters, secondary metabolites production, and antioxidant activity in callus cultures of Artemisia absinthium L.

2021 ◽  
Vol 10 (1) ◽  
pp. 61-72
Author(s):  
Khizar Hayat ◽  
Shahid Ali ◽  
Saif Ullah ◽  
Yujie Fu ◽  
Mubashir Hussain
Keyword(s):  
Antioxidant Activity ◽  
Copper Nanoparticles ◽  
Biomass Accumulation ◽  
Callus Cultures ◽  
Total Phenolic ◽  
Ag Nps ◽  
Artemisia Absinthium ◽  
Culture Production ◽  
Metabolites Production ◽  
Induced Changes

Abstract Artemisia absinthium L. is a highly medicinal plant with a broad range of biomedical applications. A. absinthium callus cultures were established in response to bio-fabricated single NPs (Ag and Cu) or a combination of both NPs (Ag and Cu) in different ratios (1:2, 2:1, 1:3, and 3:1) along with thidiazuron (TDZ) (4 mg/L) to elicit the biomass accumulation, production of non-enzymatic compounds, antioxidative enzymes, and antioxidant activity. Silver and copper nanoparticles (Ag and Cu NPs) were synthesized using the leaves of Moringa oleifera as reducing and capping agent and further characterized through UV-Visible spectroscopy and SEM. The 30 µg/L suspension of Ag and Cu NPs (1:2, 2:1) and 4 mg/L TDZ showed 100% biomass accumulation as compared to control (86%). TDZ in combination with Ag NPs enhanced biomass in the log phases of growth kinetics. The Cu NPs alone enhanced the superoxide dismutase activity (0.56 nM/min/mg FW) and peroxidase activity (0.31 nM/min/mg FW) in callus cultures. However, the combination of Ag and Cu NPs with TDZ induced significant total phenolic (7.31 µg/g DW) and flavonoid contents (9.27 µg/g DW). Furthermore, the antioxidant activity was highest (86%) in the Ag and Cu NPs (3:1) augmented media. The present study provides the first evidence of bio-fabricated single NPs (Ag and Cu) or a combination of both NPs (Ag and Cu) in different ratios (1:2, 2:1, 1:3, and 3:1) along with TDZ (4 mg/L) on the development of callus culture, production of endogenous enzymes, non-enzymatic components, and further antioxidant activity in callus cultures of A. absinthium.

scholarly journals Ag-Functionalized Si Nanowire Arrays Aligned Vertically for SERS Detection of Captured Heavy Metal Ions by BSA

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 685
Author(s):  
Ai-Huei Chiou ◽  
Jun-Luo Wei ◽  
Ssu-Han Chen
Keyword(s):  
Heavy Metal ◽  
Raman Scattering ◽  
Metal Ions ◽  
Metal Ion ◽  
Heavy Metal Ions ◽  
Great Promise ◽  
Ag Nps ◽  
Water Contact ◽  
Oh Groups ◽  
Si Nanowire

A novel surface-enhanced Raman scattering (SERS)-based probe to capture heavy metal ion (Zn2+) by bovine serum albumin (BSA) using Si-nanowire (SiNW) arrays with silver nanoparticles (AgNPs) was developed. A layer with AgNPs was deposited on the SiNW surface by RF magnetron sputtering for enhancement of SERS signals. Using a high-resolution transmission electron microscope (HRTEM), the observation reveals that the AgNP layer with depths of 30–75 nm was successfully deposited on SiNW arrays. The Ag peaks in EDS and XRD spectra of SiNW arrays confirmed the presence of Ag particles on SiNW arrays. The WCA observations showed a high affinity of the Ag–SiNW arrays immobilized with BSA (water contact angle (WCA) = 87.1°) and ZnSO4 (WCA = 8.8°). The results of FTIR analysis illustrate that the conjugate bonds exist between zinc sulfate (ZnSO4) and –OH groups/–NH groups of BSA. The resulting SiNWs/Ag NPs composite interfaces showed large Raman scattering enhancement for the capture of heavy metal ions by BSA with a detection of 0.1 μM. BSA and ZnSO4 conjugations, illustrating specific SERS spectra with high sensitivity, which suggests great promise in developing label-free biosensors.

scholarly journals Zinc Oxide and Silver Nanoparticle Effects on Intestinal Bacteria

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2489
Author(s):  
Ami Yoo ◽  
Mengshi Lin ◽  
Azlin Mustapha
Keyword(s):  
Electron Microscopy ◽  
Zinc Oxide ◽  
Morphological Changes ◽  
Intestinal Bacteria ◽  
Bacterial Cells ◽  
Ag Nps ◽  
Zno Nps ◽  
Bifidobacterium Animalis ◽  
Transmission Electron

The application of nanoparticles (NPs) for food safety is increasingly being explored. Zinc oxide (ZnO) and silver (Ag) NPs are inorganic chemicals with antimicrobial and bioactive characteristics and have been widely used in the food industry. However, not much is known about the behavior of these NPs upon ingestion and whether they inhibit natural gut microflora. The objective of this study was to investigate the effects of ZnO and Ag NPs on the intestinal bacteria, namely Escherichia coli, Lactobacillus acidophilus, and Bifidobacterium animalis. Cells were inoculated into tryptic soy broth or Lactobacilli MRS broth containing 1% of NP-free solution, 0, 12, 16, 20 mM of ZnO NPs or 0, 1.8, 2.7, 4.6 mM Ag NPs, and incubated at 37 °C for 24 h. The presence and characterization of the NPs on bacterial cells were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDS). Membrane leakage and cell viability were assessed using a UV-visible spectrophotometer and confocal electron microscope, respectively. Numbers of treated cells were within 1 log CFU/mL less than those of the controls for up to 12 h of incubation. Cellular morphological changes were observed, but many cells remained in normal shapes. Only a small amount of internal cellular contents was leaked due to the NP treatments, and more live than dead cells were observed after exposure to the NPs. Based on these results, we conclude that ZnO and Ag NPs have mild inhibitory effects on intestinal bacteria.

scholarly journals Toxicity and chemical transformation of silver nanoparticles in A549 lung cells: dose-rate-dependent genotoxic impact

2021 ◽  
Author(s):  
Laure Bobyk ◽  
Adeline Tarantini ◽  
David Beal ◽  
Giulia Veronesi ◽  
Isabelle Kieffer ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Silver Nanoparticles ◽  
Dose Rate ◽  
Cell Metabolism ◽  
A549 Cells ◽  
Dna Integrity ◽  
Lung Cells ◽  
Ag Nps ◽  
Rate Dependent ◽  
A549 Lung

Acute exposure of A549 cells to Ag-NPs induces stronger effects on DNA integrity, ROS level, cell metabolism and cell cycle than repeated exposure. Ag-NPs dissolves in both exposure conditions and Ag ions recombine with thiolated proteins.

scholarly journals Recycling silver nanoparticle debris from laser ablation of silver nanowire in liquid media toward minimum material waste

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
June Sik Hwang ◽  
Jong-Eun Park ◽  
Gun Woo Kim ◽  
Hyeono Nam ◽  
Sangseok Yu ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Silver Nanoparticle ◽  
Building Materials ◽  
Raw Materials ◽  
Silver Nanowires ◽  
Silver Nanowire ◽  
Liquid Media ◽  
Ag Nps ◽  
Laser Patterning ◽  
Inexpensive Procedure

AbstractAs silver nanowires (Ag NWs) are usually manufactured by chemical synthesis, a patterning process is needed to use them as functional devices. Pulsed laser ablation is a promising Ag NW patterning process because it is a simple and inexpensive procedure. However, this process has a disadvantage in that target materials are wasted owing to the subtractive nature of the process involving the removal of unnecessary materials, and large quantities of raw materials are required. In this study, we report a minimum-waste laser patterning process utilizing silver nanoparticle (Ag NP) debris obtained through laser ablation of Ag NWs in liquid media. Since the generated Ag NPs can be used for several applications, wastage of Ag NWs, which is inevitable in conventional laser patterning processes, is dramatically reduced. In addition, electrophoretic deposition of the recycled Ag NPs onto non-ablated Ag NWs allows easy fabrication of junction-enhanced Ag NWs from the deposited Ag NPs. The unique advantage of this method lies in using recycled Ag NPs as building materials, eliminating the additional cost of junction welding Ag NWs. These fabricated Ag NW substrates could be utilized as transparent heaters and stretchable TCEs, thereby validating the effectiveness of the proposed process.

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