scholarly journals X-ray Structure Elucidation of a Pt-Metalloporphyrin and Its Application for Obtaining Sensitive AuNPs-Plasmonic Hybrids Capable of Detecting Triiodide Anions

2019 ◽  
Vol 20 (3) ◽  
pp. 710 ◽  
Author(s):  
Eugenia Fagadar-Cosma ◽  
Anca Lascu ◽  
Sergiu Shova ◽  
Mirela-Fernanda Zaltariov ◽  
Mihaela Birdeanu ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Synergistic Effects ◽  
Ion Concentration ◽  
Detection Methods ◽  
Sensitive Material ◽  
X Ray ◽  
Spectrophotometric Methods ◽  
Sensing Material ◽  
Physiological Tests ◽  
Molecule Conformation

The development of UV–vis spectrophotometric methods based on metalloporphyrins for fast, highly sensitive and selective anion detection, which avoids several of the practical challenges associated with other detection methods, is of tremendous importance in analytical chemistry. In this study, we focused on achieving a selective optical sensor for triiodide ion detection in traces based on a novel hybrid material comprised of Pt(II) 5,10,15,20-tetra(4-methoxy-phenyl)-porphyrin (PtTMeOPP) and gold nanoparticles (AuNPs). This sensor has high relevance in medical physiological tests. The structure of PtTMeOPP was investigated by single crystal X-ray diffraction in order to understand the metal surroundings and the molecule conformation and to assess if it qualifies as a potential sensitive material. It was proven that the Pt-porphyrin generated 1D H-bond supramolecular chains due to the weak C-H···O intermolecular hydrogen bonding. The presence of ordered voids in the crystal encouraged us to use PtTMeOPP as the sensing material for triiodide ion and to enhance its potential in a novel AuNPs/PtTMeOPP hybrid by the synergistic effects provided by the plasmonic gold nanoparticles. The spectrophotometric sensor is characterized by a detection limit of 1.5 × 10−9 M triiodide ion concentration and a remarkable confidence coefficient of 99.98%.

scholarly journals Biosynthesis of Silver and Gold Nanoparticles Using Aqueous Extract of Codonopsis pilosula Roots for Antibacterial and Catalytic Applications

2020 ◽  
Vol 2020 ◽  
pp. 1-18
Author(s):  
Van-Dat Doan ◽  
Bao-An Huynh ◽  
Thanh-Danh Nguyen ◽  
Xuan-Thang Cao ◽  
Van-Cuong Nguyen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Gold Nanoparticles ◽  
Aqueous Extract ◽  
Metal Ion ◽  
Metallic Nanoparticles ◽  
Ion Concentration ◽  
Gram Negative ◽  
X Ray ◽  
Codonopsis Pilosula ◽  
Vis Spectroscopy

In this study, biogenic silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) were synthesized by a green approach using an aqueous extract from Codonopsis pilosula (CP) roots as a reducing and stabilizing agent. The formation of CP-AgNPs and CP-AuNPs was confirmed and optimized by UV-Vis spectroscopy. The CP-AgNPs and CP-AuNPs obtained under optimum conditions of metal ion concentration, reaction temperature, and reaction time were characterized by high-resolution transition electron microscopy (HR-TEM), selected area electron diffraction (SAED) analysis, field-emission scan electron microscopy (FE-SEM), powder X-ray diffraction (XRD) analysis, Fourier transform infrared (FTIR) spectroscopy, dispersive X-ray spectroscopy (EDX), and dynamic light scattering (DLS) method. It has been found that the biosynthesized CP-AgNPs and CP-AuNPs were formed in spherical shape with an average size of 10±2.5 nm and 20±3.2 nm, respectively. The biosynthesized metallic nanoparticles exhibited selective bacterial activity against three bacterial strains including two Gram-positive bacteria of Bacillus subtilis and Staphylococcus aureus and one Gram-negative bacteria of Escherichia coli. Meanwhile, there was no antibacterial activity detected toward Gram-negative Salmonella enteritidis. CP-AgNPs and CP-AuNPs also manifested an excellent catalytic performance in the reduction of 1,4-dinitrobenzene, 2-nitrophenol, 3-nitrophenol, and 4-nitrophenol.

scholarly journals Nanomaterial-Enabled Sensors and Therapeutic Platforms for Reactive Organophosphates

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 224
Author(s):  
Seok Ki Choi
Keyword(s):  
Unmet Need ◽  
Detection Methods ◽  
Treatment Modalities ◽  
Primary Interest ◽  
Biochemical Basis ◽  
Considerable Potential ◽  
Agricultural Pesticides ◽  
Design Concepts ◽  
Spectrophotometric Methods ◽  
The Status

Unintended exposure to harmful reactive organophosphates (OP), which comprise a group of nerve agents and agricultural pesticides, continues to pose a serious threat to human health and ecosystems due to their toxicity and prolonged stability. This underscores an unmet need for developing technologies that will allow sensitive OP detection, rapid decontamination and effective treatment of OP intoxication. Here, this article aims to review the status and prospect of emerging nanotechnologies and multifunctional nanomaterials that have shown considerable potential in advancing detection methods and treatment modalities. It begins with a brief introduction to OP types and their biochemical basis of toxicity followed by nanomaterial applications in two topical areas of primary interest. One topic relates to nanomaterial-based sensors which are applicable for OP detection and quantitative analysis by electrochemical, fluorescent, luminescent and spectrophotometric methods. The other topic is directed on nanotherapeutic platforms developed as OP remedies, which comprise nanocarriers for antidote drug delivery and nanoscavengers for OP inactivation and decontamination. In summary, this article addresses OP-responsive nanomaterials, their design concepts and growing impact on advancing our capability in the development of OP sensors, decontaminants and therapies.

scholarly journals X-ray Fluorescence Uptake Measurement of Functionalized Gold Nanoparticles in Tumor Cell Microsamples

2021 ◽  
Vol 22 (7) ◽  
pp. 3691
Author(s):  
Oliver Schmutzler ◽  
Sebastian Graf ◽  
Nils Behm ◽  
Wael Y. Mansour ◽  
Florian Blumendorf ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Irradiation Time ◽  
High Sensitivity ◽  
Nanoparticle Uptake ◽  
X Ray ◽  
Functionalized Gold Nanoparticles ◽  
Uptake Measurement ◽  
Prostate Tumor Cells ◽  
Non Destructive

Quantitative cellular in vitro nanoparticle uptake measurements are possible with a large number of different techniques, however, all have their respective restrictions. Here, we demonstrate the application of synchrotron-based X-ray fluorescence imaging (XFI) on prostate tumor cells, which have internalized differently functionalized gold nanoparticles. Total nanoparticle uptake on the order of a few hundred picograms could be conveniently observed with microsamples consisting of only a few hundreds of cells. A comparison with mass spectroscopy quantification is provided, experimental results are both supported and sensitivity limits of this XFI approach extrapolated by Monte-Carlo simulations, yielding a minimum detectable nanoparticle mass of just 5 pg. This study demonstrates the high sensitivity level of XFI, allowing non-destructive uptake measurements with very small microsamples within just seconds of irradiation time.

scholarly journals Pristine and Magnetic Kenaf Fiber Biochar for Cd2+ Adsorption from Aqueous Solution

2021 ◽  
Vol 18 (15) ◽  
pp. 7949
Author(s):  
Anwar Ameen Hezam Saeed ◽  
Noorfidza Yub Harun ◽  
Suriati Sufian ◽  
Muhammad Roil Bilad ◽  
Zaki Yamani Zakaria ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Photoelectron Spectroscopy ◽  
Textural Properties ◽  
Ion Concentration ◽  
Solution Temperature ◽  
Maximum Adsorption Capacity ◽  
Magnetic Biochar ◽  
X Ray ◽  
Study Results ◽  
Capacity Surface

Development of strategies for removing heavy metals from aquatic environments is in high demand. Cadmium is one of the most dangerous metals in the environment, even under extremely low quantities. In this study, kenaf and magnetic biochar composite were prepared for the adsorption of Cd2+. The synthesized biochar was characterized using (a vibrating-sample magnetometer VSM), Scanning electron microscopy (SEM), X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The adsorption batch study was carried out to investigate the influence of pH, kinetics, isotherm, and thermodynamics on Cd2+ adsorption. The characterization results demonstrated that the biochar contained iron particles that help in improving the textural properties (i.e., surface area and pore volume), increasing the number of oxygen-containing groups, and forming inner-sphere complexes with oxygen-containing groups. The adsorption study results show that optimum adsorption was achieved under pH 5–6. An increase in initial ion concentration and solution temperature resulted in increased adsorption capacity. Surface modification of biochar using iron oxide for imposing magnetic property allowed for easy separation by external magnet and regeneration. The magnetic biochar composite also showed a higher affinity to Cd2+ than the pristine biochar. The adsorption data fit well with the pseudo-second-order and the Langmuir isotherm, with the maximum adsorption capacity of 47.90 mg/g.

scholarly journals The Synergistic Effects of Alloying on the Performance and Stability of Co3Mo and Co7Mo6 for the Electrocatalytic Hydrogen Evolution Reaction

Hydrogen ◽  
2020 ◽  
Vol 1 (1) ◽  
pp. 11-21
Author(s):  
Youyi Sun ◽  
Alexey Y. Ganin
Keyword(s):  
Hydrogen Evolution ◽  
Synergistic Effects ◽  
Alkaline Media ◽  
Price Of Stability ◽  
X Ray Diffraction ◽  
Free Standing ◽  
X Ray ◽  
Current Decay ◽  
Earth Abundant ◽  
Current Densities

Metal alloys have become a ubiquitous choice as catalysts for electrochemical hydrogen evolution in alkaline media. However, scarce and expensive Pt remains the key electrocatalyst in acidic electrolytes, making the search for earth-abundant and cheaper alternatives important. Herein, we present a facile and efficient synthetic route towards polycrystalline Co3Mo and Co7Mo6 alloys. The single-phased nature of the alloys is confirmed by X-ray diffraction and electron microscopy. When electrochemically tested, they achieve competitively low overpotentials of 115 mV (Co3Mo) and 160 mV (Co7Mo6) at 10 mA cm−2 in 0.5 M H2SO4, and 120 mV (Co3Mo) and 160 mV (Co7Mo6) at 10 mA cm−2 in 1 M KOH. Both alloys outperform Co and Mo metals, which showed significantly higher overpotentials and lower current densities when tested under identical conditions, confirming the synergistic effect of the alloying. However, the low overpotential in Co3Mo comes at the price of stability. It rapidly becomes inactive when tested under applied potential bias. On the other hand, Co7Mo6 retains the current density over time without evidence of current decay. The findings demonstrate that even in free-standing form and without nanostructuring, polycrystalline bimetallic electrocatalysts could challenge the dominance of Pt in acidic media if ways for improving their stability were found.

scholarly journals Magnetically Recyclable Wool Keratin Modified Magnetite Powders for Efficient Removal of Cu2+ Ions from Aqueous Solutions

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1068
Author(s):  
Xinyue Zhang ◽  
Yani Guo ◽  
Wenjun Li ◽  
Jinyuan Zhang ◽  
Hailiang Wu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Ion Concentration ◽  
Bet Surface Area ◽  
Chemical Compositions ◽  
Ion Adsorption ◽  
X Ray ◽  
Wool Keratin

The treatment of wastewater containing heavy metals and the utilization of wool waste are very important for the sustainable development of textile mills. In this study, the wool keratin modified magnetite (Fe3O4) powders were fabricated by using wool waste via a co-precipitation technique for removal of Cu2+ ions from aqueous solutions. The morphology, chemical compositions, crystal structure, microstructure, magnetism properties, organic content, and specific surface area of as-fabricated powders were systematically characterized by various techniques including field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometer (VSM), thermogravimetric (TG) analysis, and Brunauer–Emmett–Teller (BET) surface area analyzer. The effects of experimental parameters such as the volume of wool keratin hydrolysate, the dosage of powder, the initial Cu2+ ion concentration, and the pH value of solution on the adsorption capacity of Cu2+ ions by the powders were examined. The experimental results indicated that the Cu2+ ion adsorption performance of the wool keratin modified Fe3O4 powders exhibited much better than that of the chitosan modified ones with a maximum Cu2+ adsorption capacity of 27.4 mg/g under favorable conditions (0.05 g powders; 50 mL of 40 mg/L CuSO4; pH 5; temperature 293 K). The high adsorption capacity towards Cu2+ ions on the wool keratin modified Fe3O4 powders was primarily because of the strong surface complexation of –COOH and –NH2 functional groups of wool keratins with Cu2+ ions. The Cu2+ ion adsorption process on the wool keratin modified Fe3O4 powders followed the Temkin adsorption isotherm model and the intraparticle diffusion and pseudo-second-order adsorption kinetic models. After Cu2+ ion removal, the wool keratin modified Fe3O4 powders were easily separated using a magnet from aqueous solution and efficiently regenerated using 0.5 M ethylene diamine tetraacetic acid (EDTA)-H2SO4 eluting. The wool keratin modified Fe3O4 powders possessed good regenerative performance after five cycles. This study provided a feasible way to utilize waste wool textiles for preparing magnetic biomass-based adsorbents for the removal of heavy metal ions from aqueous solutions.

scholarly journals Contrast-Enhanced X-ray Detection of Microcalcifications in Radiographically Dense Mammary Tissue Using Targeted Gold Nanoparticles

ACS Nano ◽  
2015 ◽  
Vol 9 (9) ◽  
pp. 8923-8932 ◽  
Author(s):  
Lisa E. Cole ◽  
Tracy Vargo-Gogola ◽  
Ryan K. Roeder
Keyword(s):  
Gold Nanoparticles ◽  
Mammary Tissue ◽  
X Ray ◽  
Contrast Enhanced

Gold nanoparticles in the clinical laboratory: principles of preparation and applications

2012 ◽  
Vol 50 (2) ◽  
Author(s):  
Hassan M.E. Azzazy ◽  
Mai M.H. Mansour ◽  
Tamer M. Samir ◽  
Ricardo Franco
Keyword(s):  
Gold Nanoparticles ◽  
Clinical Laboratory ◽  
Sensitive Detection ◽  
Detection Methods ◽  
Practical Applications ◽  
Molecular Assays ◽  
Detection Of Biomarkers

AbstractIn order to meet the challenges of effective healthcare, the clinical laboratory is constantly striving to improve testing sensitivity while reducing the required time and cost. Gold nanoparticles (AuNPs) are proposed as one of the most promising tools to meet such goals. They have unique optophysical properties which enable sensitive detection of biomarkers, and are easily amenable to modification for use in different assay formats including immunoassays and molecular assays. Additionally, their preparation is relatively simple and their detection methods are quite versatile. AuNPs are showing substantial promise for effective practical applications and commercial utilization is already underway. This article covers the principles of preparation of AuNPs and their use for development of different diagnostic platforms.

scholarly journals Green Synthesis of Silver and Gold Nanoparticles via Sargassum serratifolium Extract for Catalytic Reduction of Organic Dyes

Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 347
Author(s):  
Beomjin Kim ◽  
Woo Chang Song ◽  
Sun Young Park ◽  
Geuntae Park
Keyword(s):  
Gold Nanoparticles ◽  
Green Synthesis ◽  
Catalytic Reduction ◽  
Organic Dyes ◽  
Low Cost ◽  
Inorganic Nanoparticles ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Sargassum Serratifolium

The green synthesis of inorganic nanoparticles (NPs) using bio-materials has attained enormous attention in recent years due to its simple, eco-friendly, low-cost and non-toxic nature. In this work, silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) were synthesized by the marine algae extract, Sargassum serratifolium (SS). The characteristic studies of bio-synthesized SS-AgNPs and SS-AuNPs were carried out by using ultraviolet–visible (UV–Vis) absorption spectroscopy, dynamic light scattering (DLS), high-resolution transmission electron microscope (HR-TEM), selected area electron diffraction (SAED), energy-dispersive X-ray spectroscopy (EDX), X-ray powder diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). Phytochemicals in the algae extract, such as meroterpenoids, acted as a capping agent for the NPs’ growth. The synthesized Ag and Au NPs were found to have important catalytic activity for the degradation of organic dyes, including methylene blue, rhodamine B and methyl orange. The reduction of dyes by SS-AgNPs and -AuNPs followed the pseudo-first order kinetics.

Synthesis and Study the Properties of a Solar Cell of Gold Nanoparticles Prepared in a Simple Chemical Way

2021 ◽  
Vol 19 (11) ◽  
pp. 66-71
Author(s):  
Maithm A. Obaid ◽  
Suha A Fadaam ◽  
Osama S. Hashim
Keyword(s):  
Electron Microscopy ◽  
Gold Nanoparticles ◽  
Chemical Method ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Casting Method ◽  
X Ray ◽  
Transmission Electron ◽  
Simple Chemical ◽  
Scanning Electron

The aim of this study is to prepare gold nanoparticles by a simple chemical method at a temperature of 70°C. The solution was dried on glass basest by Casting method, the rate of five drops per sample At a temperature 100 C. Then the structural and optical properties have been confirmed by X-ray diffraction, scanning electron microscopy (SEM) and Transmission Electron microscope (TEM), Fourier Transform Infrared Spectroscopy (FTIR) and spectrum.

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