scholarly journals Silver Nanoparticles: Green Synthesis, Characterization, and Their Usage in Determination of Mercury Contamination in Seafoods

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Muhammad Ahad Ahmed ◽  
Najmul Hasan ◽  
Shaikh Mohiuddin

We demonstrate that silver nanoparticles undergo an interaction with Hg2+ found in traces. The PEG-PVP-stabilized Ag nanoparticles were successfully synthesized via a reduction approach and characterized with surface plasmon resonance UV/Vis spectroscopy. By utilizing the redox reaction between Ag nanoparticles and Hg2+, and the resulted decrease in UV/Vis signal, we develop a colorimetric method for detection of Hg2+ ion. A linear and inversely proportional relationship was found between the absorbance intensity of the Ag nanoparticles and the concentration of Hg2+ ion over the range from 10 ppm to 1 ppm at absorption on 411 nm. The detection limit for Hg2+ ions in homogeneous aqueous solutions is estimated to be 1 ppm. This system shows excellent selectivity for Hg2+. The results found have potential implications in the development of new colorimetric sensors for easy and selective detection and monitoring of mercuric ions in aqueous solutions. The proposed method was successfully applied to quantify the amount of mercury in seafood.

2013 ◽  
Vol 756 ◽  
pp. 99-105
Author(s):  
Rajasingam Ratnamalar ◽  
Mustapha Mariatti ◽  
Zulkifli Ahmad ◽  
Sharif Zein Sharif Hussein

This work reports a simple chemical reduction route for the preparation of uniformed Ag nanoparticles whereby a fine control over the sizes of the Ag nanoparticles was studied by varying the concentrations of the reducing agents used. In characterization, UV-Vis spectroscopy showed the changes in optical properties of the Ag nanoparticles with regards to their sizes, where as the XRD patterns of the synthesized Ag nanoparticles confirmed the distinct peaks approximately at 2θ = 38.1°, 44.3°, 64.4°, 77.4°, and 81.5 representing Bragg’s reflections from (111), (200), (220), (311), and (222) planes of the face centred cubic lattice phase. This route of synthesis is feasible to produce Ag nanoparticles with diameters in the range of 30-45 nm.


2019 ◽  
Vol 8 (3) ◽  
pp. 576-585

In the present study silver nanoparticles (AgNPs) have been synthesized through the cell-free extracts of the rooftop dwelling cyanobacterium Scytonema geitleri HKAR-12. UV-VIS spectroscopy, FTIR, X-ray diffraction, SEM and TEM were used for the determination of morphological, structural and optical properties of synthesized AgNPs. Extracts of Scytonema geitleri HKAR-12 have the ability to reduce AgNO3 to Ag0. Sharp peak at 422 nm indicated the rapid synthesis of AgNPs. FTIR results showed the presence of different groups responsible for the reduction of AgNO3 to AgNPs. XRD pattern confirmed the crystalline nature of AgNPs. SEM showed the bead shape structure of AgNPs. TEM confirmed the actual size of AgNPs to be ranging between 9-17 nm. AgNPs showed antibacterial activity against Pseudomonas aeruginosa, Escherichia coli strain1 and E. coli strain 2 and 11 μg/mL of AgNPs effectively inhibited the growth of MCF-7 cells. Hence, Scytonema geitleri HKAR-12, isolated from the rooftop could serve as a desirable biological candidate for convenient and cheap production of AgNPs having antimicrobial and anti-cancerous properties.


2017 ◽  
Vol 17 (3) ◽  
pp. 439 ◽  
Author(s):  
Roto Roto ◽  
Marcelina Marcelina ◽  
Nurul Hidayat Aprilita ◽  
Mudasir Mudasir ◽  
Taufik Abdillah Natsir ◽  
...  

Analysis of Fe3+ ion present in aqueous solutions is always of interests. Recently, this ion has been analyzed by colorimetric methods using colloid of silver nanoparticles (AgNPs) in capping agents of polymers. The reaction mechanism between AgNPs and Fe3+ is still subject to the further investigation. In this work, 1,10-phenanthroline was used to probe the reaction mechanism between AgNPs and Fe3+ ion in the solution. The colloids of AgNPs were prepared in the polyvinyl alcohol (PVA) solution and reacted with Fe3+. The colloid surface plasmon absorbance decreases linearly along with the increase in Fe3+ concentration. The addition of 1,10-phenanthroline to mixture changes the solution to red, indicating that the reaction produces Fe2+. This suggests that the reduction of the AgNPs absorbance is the result of oxidation of the Ag nanoparticles along with the reduction of Fe3+.


2012 ◽  
Vol 585 ◽  
pp. 134-138 ◽  
Author(s):  
Alisha Goyal ◽  
Jyoti Rozra ◽  
Isha Saini ◽  
Pawan K. Sharma ◽  
Annu Sharma

Nanocomposite films of Poly (methylmethacrylate) with different concentration of silver nanoparticles were prepared by ex-situ method. Firstly, silver nanoparticles were obtained by reducing the aqueous solution of silver nitrate with sodium borohydride then Ag-PMMA films were prepared by mixing colloidal solution of silver nanoparticles with solution of polymer. Thin solid films were structurally characterized using UV-VIS spectroscopy and TEM. The appearance of surface plasmon resonance peak, characteristic of silver nanoparticles at 420 nm in UV-VIS absorption spectra of Ag-PMMA films confirms the formation of Ag-PMMA nanocomposite. TEM showed Ag nanoparticles of average size 8 nm embedded in PMMA matrix. Analysis of absorption and reflection data indicates towards the reduction in optical band gap and increase in refractive index of the resulting nanocomposite. The synthesized Ag-PMMA nanocomposite has been found to be more conducting than PMMA as ascertained using I-V studies. The decrease in band gap and increase in conductivity can be correlated due to the formation of localized electronic states in PMMA matrix due to insertion of Ag nanoparticles. The PMMA thin films with dispersed silver nanoparticles may be useful for nanophotonic devices.


2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Amer A. G. Al Abdel Hamid ◽  
Mohammad Al-Khateeb ◽  
Ziyad A. Tahat ◽  
Mahmoud Qudah ◽  
Safwan M. Obeidat ◽  
...  

A new ruthenium(II) complex (cis-ruthenium-bis[2,2′-bipyridine]-bis[4-aminothiophenol]-bis[hexafluorophosphate]) has been synthesized and characterized using standard analytical and spectroscopic techniques, FTIR, 1H and 13C-NMR, UV/vis, elemental analysis, conductivity measurements, and potentiometric titration. Investigation of the synthesized complex with metal ions showed that this complex has photochemical properties that are selective and sensitive toward the presence of mercuric ion in aqueous solution. The detection limit for mercuric ions using UV/vis spectroscopy was estimated to be ~ 0.4 ppm. The results presented herein may have an important implication in the development of a spectroscopic selective detection for mercuric ions in aqueous solution.


2012 ◽  
Vol 4 (10) ◽  
pp. 3407 ◽  
Author(s):  
M. Elavarasi ◽  
Madona L. Paul ◽  
A. Rajeshwari ◽  
N. Chandrasekaran ◽  
A. B. Mandal ◽  
...  

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
C. Q. Zhang ◽  
Y. M. Wang ◽  
S. Z. Li ◽  
X. D. Feng ◽  
L. H. Liu ◽  
...  

A series of novel composite microfibers composed of β-cyclodextrin (β-CDs) functionalized POM (polyoxymethylene) were prepared using electrospining technology with a mixture of hexafluoroisopropanol (HFIP) and N,N-dimethylformamide (DMF) as solvent. The concentration of β-CDs with respect to the POM was varied from 0 to 50 wt.%. The effect of β-CDs content on the morphology of POM/β-CD composite microfiber was investigated. The results showed that the introduction of β-CDs reduced the surface roughness and porosity of the microfibers, and the morphology of the fibers was changed. The increase of β-CDs content from 10% to 50% has led to increased average diameter of POM/β-CD composite fiber from 2.1 μm to 6.4 μm. The mechanical properties of the blend fiber mats were further investigated. In addition, silver nanoparticles were introduced to the POM/β-CD composite microfiber matrices during electrospinning. The POM/β-CD composite fiber allows CDs to form host–guest complexes with various small molecules and macromolecules. The TEM, SEM, XRD, and XPS were utilized to characterize the prepared samples. The data suggest that Ag nanoparticles were homogeneously distributed within the POM/β-CD fibers, and no aggregation was observed. The catalytic activity of Ag nanoparticles was tracked by ultraviolet-visible (UV-vis) spectroscopy which showed excellent catalytic degradation performance of organic dyes in the presence of NaBH4. The Ag/POM/β-CD mats are promising for use in waste treatment, molecular recognition, catalysis, and so on.


2021 ◽  
Vol 21 (4) ◽  
pp. 990
Author(s):  
Henry Fonda Aritonang ◽  
Talita Kojong ◽  
Harry Koleangan ◽  
Audy Denny Wuntu

This research was focused on the discovery of new environmentally friendly sensors based on nanoscale materials whose main purpose was to detect the presence of heavy metals in aqueous solutions. The environmentally friendly extracellular biosynthetic technique was applied to produce silver nanoparticles (AgNps). The reducing agents used were distilled water and ethanol extract obtained from fresh leaves of Lantana camara. The silver-containing extracts (Ag-extract) were then used to detect the presence of Hg2+, Cu2+, Pb2+, and Mn2+ in aqueous solutions by the colorimetric method using UV-visible spectroscopy. The colloidal synthesis of AgNPs was then monitored by the same method. The spectrum obtained showed peaks between 430 and 450 nm according to the Plasmon absorbance of AgNP. AgNPs' size and shape were characterized using the Transmission Electron Microscopy (TEM) technique, which showed the average size varies from 1.6 to 25 nm. The colorimetric data showed that Ag-extract, both of distilled water or ethanol solvents, was the best for detecting the presence of Hg2+ followed by Mn2+. On the other hand, Ag-extract in distilled water cannot detect Cu2+, Pb2+, and Mn2+ ions, while almost all Ag-extracts in ethanol solvents could identify the presence of these metals.


2015 ◽  
Vol 7 (2) ◽  
pp. 566-572 ◽  
Author(s):  
Yingjie Ye ◽  
Yi Guo ◽  
Yuan Yue ◽  
Hanjing Huang ◽  
Longtao Zhao ◽  
...  

A colorimetric method for the fast, sensitive and selective detection of Cu2+ions with silver nanoparticles is proposed based on a specific Cu2+-catalyzed oxidation reaction.


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