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Mutaf, Tuğçe, Gülizar Çalışkan, Suphi Şurişvan Öncel i Murat Elibol. "Green synthesis of metal nanoparticles by microalgae". Ege Journal of Fisheries and Aquatic Sciences 40, nr 1 (15.03.2023): 81–89. http://dx.doi.org/10.12714/egejfas.40.1.12.
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Green synthesis of metal nanoparticles through biological resources has attracted attention in recent years. The main reason for that, a lot of toxic chemicals as reducing and stabilizing agents are used in physical and chemical methods which are known as conventional methods. Organisms such as plants, fungi, bacteria, and algae are alternative sources for green nanoparticle synthesis because of their more eco-friendly nature and not be a threat to human health. Microalgae as aquatic microorganisms have been added into the formulations of food, cosmetics, and pharmaceutical for many years, due to their high value-added metabolites such as proteins, vitamins, pigments, fatty acids, intracellular and extracellular polysaccharides. In addition, microalgae have a high potential in biogenic nanoparticle synthesis because of their metal ions accumulation capability, phytoremediation potential, and rich in intracellular and extracellular metabolites that will reduce metal ions to elemental state. In recent years, the number of studies, focused on silver, gold, titanium, zinc, iron, etc. nanoparticle synthesis from many microalgae species by intracellular and extracellular pathways has increased. This review article aims to provide a brief outline of microalgae and cyanobacteria species studied in the context of nanoparticle synthesis, different approaches for nanoparticle synthesis from microalgae, the mechanism of nanoparticle synthesis, and basic characterization principles and antimicrobial activities of nanoparticles produced by green synthesis.
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Adeyemi, Jerry O., Ayodeji O. Oriola, Damian C. Onwudiwe i Adebola O. Oyedeji. "Plant Extracts Mediated Metal-Based Nanoparticles: Synthesis and Biological Applications". Biomolecules 12, nr 5 (24.04.2022): 627. http://dx.doi.org/10.3390/biom12050627.
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The vastness of metal-based nanoparticles has continued to arouse much research interest, which has led to the extensive search and discovery of new materials with varying compositions, synthetic methods, and applications. Depending on applications, many synthetic methods have been used to prepare these materials, which have found applications in different areas, including biology. However, the prominent nature of the associated toxicity and environmental concerns involved in most of these conventional methods have limited their continuous usage due to the desire for more clean, reliable, eco-friendly, and biologically appropriate approaches. Plant-mediated synthetic approaches for metal nanoparticles have emerged to circumvent the often-associated disadvantages with the conventional synthetic routes, using bioresources that act as a scaffold by effectively reducing and stabilizing these materials, whilst making them biocompatible for biological cells. This capacity by plants to intrinsically utilize their organic processes to reorganize inorganic metal ions into nanoparticles has thus led to extensive studies into this area of biochemical synthesis and analysis. In this review, we examined the use of several plant extracts as a mediating agent for the synthesis of different metal-based nanoparticles (MNPs). Furthermore, the associated biological properties, which have been suggested to emanate from the influence of the diverse metabolites found in these plants, were also reviewed.
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Peña-Parás, Laura, Demófilo Maldonado-Cortés, Jaime Taha-Tijerina, Patricio García-Pineda, Gerardo Tadeo Garza, Mariana Irigoyen, Jorge Gutiérrez i Dario Sánchez. "Extreme pressure properties of nanolubricants for metal-forming applications". Industrial Lubrication and Tribology 68, nr 1 (8.02.2016): 30–34. http://dx.doi.org/10.1108/ilt-05-2015-0069.
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Purpose – The purpose of this paper is to evaluate the extreme pressure properties of CuO and TiO2 nanoparticle additives with the incorporation of a surfactant within a synthetic fluid for metal-forming applications. Design/methodology/approach – The paper studies the effect of CuO and TiO2 nanoparticle additives at various concentrations (0.01, 0.05 and 0.10 wt. per cent) in a synthetic lubricant fluid under extreme pressure conditions. Oleic acid surfactant is added to the nanolubricant to improve dispersion and stability of nanoparticles. Extreme pressure tribological tests are performed on a four-ball T-02 tribotester according to the ITEePib Polish method for testing lubricants under conditions of scuffing. Findings – The results show that the addition CuO and TiO2 nanoparticles under the presence of OA resulted in an increase of the load-carrying capacity (poz) of the lubricant up to 137 and 60 per cent, respectively. The seizure load was also increased by 50 and 15 per cent, respectively. Practical implications – The results show that CuO and TiO2 nanoparticles can be successfully used as additives improving extreme pressure properties of lubricants. Originality/value – This demonstrates the potential of nanoparticle additives using surfactants for improving the extreme pressure properties of lubricants. These nanolubricants can be used for metal-forming applications like deep-drawing, achieving an increased tool life.
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Paulraj, Prabhavathi, Sankareswaran Muruganantham, Anbalagan S, Manikandan A i Karthikeyan G. "GREEN SYNTHESIS AND CHARACTERIZATION OF SILVER NANOPARTICLES FROM WITHANIA SOMNIFERA (L.) DUNAL". Asian Journal of Pharmaceutical and Clinical Research 9, nr 5 (1.09.2016): 34. http://dx.doi.org/10.22159/ajpcr.2016.v9i5.13204.
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ABSTRACTThe metal nanoparticle synthesis is highly explored the field of nanotechnology. The biological methods seem to be more effective because of slowreduction rate and polydispersity of the final products. The main aim of this study is too the rapid and simplistic synthesis of silver nanoparticlesby Withania somnifera Linn. at room temperature. The exposure of reaction mixtures containing silver nitrate and dried leaf powder of W. somniferaresulted in reduction of metal ions within 5 minutes. The extracellular synthesized silver nanoparticles were characterized by ultraviolet-visible,infrared (IR) spectroscopy, X-ray diffraction studies, zeta potential, Fourier transform IR, and scanning electron microscopy. The antibacterial andantifungal studies showed significant activity as compared to their respective standards. From the results, W. somnifera sliver nanoparticle has attainedthe maximum antimicrobial against clinical pathogens and also seen very good stability of nanoparticle throughput processing. As we concluded, thistype of naturally synthesized sliver nanoparticle could be a better green revolution in medicinal chemistry.Keywords: Antimicrobial activity, Silver nanoparticles, Withania somnifera.
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Kurdish, I. K. "Natural and Synthetic Nanomaterials in Microbial Biotechnologies for Crop Production". Mikrobiolohichnyi Zhurnal 83, nr 3 (17.06.2021): 81–91. http://dx.doi.org/10.15407/microbiolj83.03.081.
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Nanoparticles of various materials (up to 100 nm in size) are characterized by a large surface area, which significantly increases their reactive properties. This makes promissing the studies of their possible application in different technologies, including those in the agricultural production sector. This review summarizes the literature on the distribution and properties of natural nanoparticles in the environment. The features of the interaction between various types of microorganisms, nanoparticles of natural minerals, oxides of metals and carbon nanoparticles are analyzed. The review also summarizes the data on the effect of nanoparticles of different origin on microorganisms, plant growth and development. It also presents the information on the effectiveness of the use of clay mineral nanoparticles in the production of complex bacterial preparations for plant growing and the prospects of using nanoparticles of metal oxides in this industry.
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Abdelrahman, Meram S., Sahar H. Nassar, Hamada Mashaly, Safia Mahmoud, Dalia Maamoun, Mohamed El-Sakhawy, Tawfik A. Khattab i Samir Kamel. "Studies of Polylactic Acid and Metal Oxide Nanoparticles-Based Composites for Multifunctional Textile Prints". Coatings 10, nr 1 (9.01.2020): 58. http://dx.doi.org/10.3390/coatings10010058.
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A novel approach toward the production of multifunctional printed technical textiles is reported. Three different metal oxides nanoparticles including titanium dioxide, magnesium oxide, and zinc oxide were prepared and characterized. Both natural wool and synthetic acrylic fibers were pretreated with the prepared metal oxide nanoparticles followed by printing using polylactic acid based paste containing acid or basic dyestuffs. Another route was applied via post-treatment of the targeted fabrics with the metal oxide nanoparticles after running the printing process. The color strength (K/S) and colorfastness properties of pretreated and post-treated printed fabrics were evaluated and compared with untreated printed fabrics. The presence of nanoparticles on a fabric surface during the coating process was found to significantly increase the color strength value of the coated textile substrates. The increased K/S value depended mainly on the nature and concentration of the applied metal oxide, as well as the nature of colorant and fabric. In addition, the applied metal oxide nanoparticles imparted the printed fabrics with good antibacterial activity, high ultraviolet protection, photocatalytic self-cleaning, and improved colorfastness properties. Those results suggest that the applied metal oxide-based nanoparticles could introduce ideal multifunctional prints for garments.
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R. Aarathy, A., M. S. Gopika i S. Savitha Pillai. "Recent Insights into the Potential of Magnetic Metal Nanostructures as Magnetic Hyperthermia Agents". Sensor Letters 18, nr 12 (1.12.2020): 861–80. http://dx.doi.org/10.1166/sl.2020.4297.
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The advancements in magnetic nanoparticle mediated hyperthermia give so many optimistic and fruitful results that make it a promising and complementary approach for the existing treatment modalities of cancer. This thermotherapy is gaining wide acceptance among the medical community compared to the conventional treatment methods. The former provides a local heat generation in the malignant tumor cells and remains non-invasive to the adjacent healthy cells. The increased heating efficiency of magnetic nanoparticles and the control of local therapeutic temperature are the main challenges of hyperthermia. Superparamagnetic Iron Oxide nanoparticles have been intensively studied and dominating in magnetic hyperthermia. Recently many researchers successfully demonstrated high heating efficiency and biocompatibility of a wide variety of magnetic metal nanoparticles and proposed as the most promising alternative for traditional iron oxides, which opens up a new avenue for magnetic metal nanoparticles in magnetic hyperthermia. The review presents the recent advancements that occurred in the field of metal nanoparticle mediated magnetic hyperthermia. The theory underlying heat generation, synthesis methods, biofunctionalization, Specific Absorption Rate studies, challenges and future perspectives of magnetic metal nanoparticles are presented. This will inspire more in-depth research and advance practical applications of metal nanoparticles in magnetic hyperthermia.
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Imran Din, Muhammad, Faria Rafique, Muhammad Sadaf Hussain, Hafiz Arslan Mehmood i Sadia Waseem. "Recent developments in the synthesis and stability of metal ferrite nanoparticles". Science Progress 102, nr 1 (marzec 2019): 61–72. http://dx.doi.org/10.1177/0036850419826799.
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This article presents a comprehensive review on the synthesis and stability of ferrite nanoparticles such as nickel ferrite (NiFe2O4), zinc ferrite (ZnFe2O4), manganese ferrite (MnFe2O4), iron ferrite (Fe2O3), cobalt ferrite (CoFe2O4) and also mixed nanoparticles. Different synthetic methods for ferrite nanoparticles have been reviewed such as co-precipitation, thermal decomposition and hydrothermal, microwave-assisted and sonochemical methods. The effect on the stability of different capping agents like canola oil, glycerol, sodium dodecyl, sodium citrate, oleic acid, Triton-100 and sodium dodecyl benzene sulfonates has also been studied.
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Kandasamy, Senthilkumar, Sampathkumar Velusamy, Pradeep Thirumoorthy, Mageshkumar Periyasamy, SenthilkumarVeerasamy, K. M. Gopalakrishnan, U. Sathish, Vallarasu Kiramani, Fathima Darras Gracy Antrini i Selvakumar Periyasamy. "Adsorption of Chromium Ions from Aqueous Solutions by Synthesized Nanoparticles". Journal of Nanomaterials 2022 (23.05.2022): 1–8. http://dx.doi.org/10.1155/2022/6214438.
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In the present manuscript, an attempt has been made to remove chromium metal ions from synthetic effluent using adsorption process. The synthesized titanium dioxide nanoparticles were used as adsorbents. Adsorption studies were performed in batch process. Various characterization of synthesized nanoparticles such as XRD analysis, optical properties of nanoparticles using UV-visible absorption spectroscopy, concentration of chemical bonds, and atomic arrangement using (FTIR) have been performed and analyzed. The dependency of adsorption percentage of metal ions and equilibrium amount of metal adsorbed with respect to pH, adsorbent dosage, initial concentration, and temperature are studied. Mechanisms of metal ion adsorption process explained by various adsorption isotherms and adsorption kinetic models. The criteria for statistical significance of correlation coefficient ( R 2 ) for fitting the experimental data to the various isotherms were tested and analyzed. The experimental results reveal that synthesized titanium dioxide nanoparticles could be used as adsorbents in order to remove chromium ions present in industrial wastewater.
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Martínez-Cabanas, María, Marta López-García, Pilar Rodríguez-Barro, Teresa Vilariño, Pablo Lodeiro, Roberto Herrero, José L. Barriada i Manuel E. Sastre de Vicente. "Antioxidant Capacity Assessment of Plant Extracts for Green Synthesis of Nanoparticles". Nanomaterials 11, nr 7 (25.06.2021): 1679. http://dx.doi.org/10.3390/nano11071679.
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In this work, water extracts from different bio-based products of plant origin were studied to evaluate their antioxidant capacity and their potential to form metal nanoparticles from aqueous solutions. Two traditional tests, the Folin–Ciocalteu assay and the DPPH radical scavenging capacity method were compared with a more recent one, SNPAC, based on the formation of silver nanoparticles. The silver nanoparticle antioxidant capacity method (SNPAC) was optimized for its application in the characterization of the extracts selected in this work; kinetic studies and extract concentration were also evaluated. The extracts were obtained from leaves of oak, eucalyptus, green tea, white and common thyme, white cedar, mint, rosemary, bay, lemon, and the seaweed Sargassum muticum. The results demonstrate that any of these three methods can be used as a quick test to identify an extract to be employed for nanoparticle formation. Additionally, we studied the synthesis of Cu, Fe, Pb, Ni, and Ag nanoparticles using eucalyptus extracts demonstrating the efficiency of this plant extract to form metallic nanoparticles from aqueous metal salt solutions. Metal nanoparticles were characterized by transmission electron microscopy and dynamic light scattering techniques.
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Cruz-Luna, Aida R., Alfonso Vásquez-López, Hugo Rojas-Chávez, Manuel A. Valdés-Madrigal, Heriberto Cruz-Martínez i Dora I. Medina. "Engineered Metal Oxide Nanoparticles as Fungicides for Plant Disease Control". Plants 12, nr 13 (27.06.2023): 2461. http://dx.doi.org/10.3390/plants12132461.
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Metal oxide nanoparticles are considered to be good alternatives as fungicides for plant disease control. To date, numerous metal oxide nanoparticles have been produced and evaluated as promising antifungal agents. Consequently, a detailed and critical review on the use of mono-, bi-, and tri-metal oxide nanoparticles for controlling phytopathogenic fungi is presented. Among the studied metal oxide nanoparticles, mono-metal oxide nanoparticles—particularly ZnO nanoparticles, followed by CuO nanoparticles —are the most investigated for controlling phytopathogenic fungi. Limited studies have investigated the use of bi- and tri-metal oxide nanoparticles for controlling phytopathogenic fungi. Therefore, more studies on these nanoparticles are required. Most of the evaluations have been carried out under in vitro conditions. Thus, it is necessary to develop more detailed studies under in vivo conditions. Interestingly, biological synthesis of nanoparticles has been established as a good alternative to produce metal oxide nanoparticles for controlling phytopathogenic fungi. Although there have been great advances in the use of metal oxide nanoparticles as novel antifungal agents for sustainable agriculture, there are still areas that require further improvement.
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YILMAZ, Ersen, Mehmet ATEŞ i Muhammed ERBAY. "Green Synthesis of Gold Nanoparticles Using Aqueous Extract of Asphodelus Aestivus, Coating with Chitosan Biopolymer and Cytotoxicity Studies". Cumhuriyet Science Journal 43, nr 3 (30.09.2022): 416–22. http://dx.doi.org/10.17776/csj.1077429.
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The green synthesis of gold nanoparticles (Au-NPs) was carried out by pouring the aqueous extract of East Anatolian origin Asphodelus aestivus plant onto aqueous gold metal ions and reducing them via single-step one- pot method. The absorption peak of the synthesized nanoparticles gave a maximum at 575 nm. All the X-ray diffraction peaks at 2θ = 38.25 , 44.46 , 64.64 and 77.20 that index to (111), (200), (220), and (311) planes verify the successful synthesis of Au-NPs. Mostly spherical shape particles showed a homogeneous distribution with size range 20±5 nm are measured using TEM. From the FTIR spectrum, the peaks are seems to be related to phenolic compounds, flavonoids, benzophenones, terpenoids and anthocyanins which assume that they could act as the reducing agents. The plant extraction, one-pot, single-step method used is environmentally safe without the role of synthetic materials which is highly potential in mild and green synthesis applications. The Au-NPs were coated with chitosan biopolymer in aquatic solution medium and verified by SEM. Then, cytotoxic investigations of the biosynthesized Au-NPs were carried out by HUVEC cells. Au-NPs were showed toxic effects on cell culture, even if in a small amount. However, chitosan biopolymer coating increased cell viability.Keywords: Gold nanoparticle, Biosynthesis, Asphodelus aestivus, Biopolymer coating, Cytotoxicity
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Lakshmi, Augustine, Athisayaraj Emi Princess Prasanna i Chinnapiyan Vedhi. "Synthesis, Characterisation and Capacitive Behaviour of Poly(3,4-ethylenedioxythiophene)-Copper Oxide Nanocomposites". Advanced Materials Research 678 (marzec 2013): 273–77. http://dx.doi.org/10.4028/www.scientific.net/amr.678.273.
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Nano particles of Copper oxide and Poly(3,4-ethylenedioxythiophene)-Copper oxide nanocomposite were prepared by chemical oxidation method. The formed metal oxide nanoparticle and polymer metal oxide nanocomposites were characterized by UV–VIS, XRD, SEM and EIS studies. The UV-VIS studies of nanoparticles and nanocomposites exhibited four peaks, two peaks are sharp and centered at 280nm and 360 nm while the other two were broaden waves obtained at 780nm and 985nm. SEM image of copper oxide nanoparticles and nanocomposite exhibits sponge-like morphologies, in addition to nanospheres, nanowires, and nanotube shapes. The grain size of the metal oxide nanoparticle and polymer metaloxide nanocomposites was calculated using Scherrer’s formula. Electrochemical impedance spectroscopy (EIS) studies revealed the high conductivity nature due to the increased surface area of the nanocomposites.
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Jyoti, N. S. Ghosh, I. Rani, S. Mujwar i B.K. Dey. "In-silico STUDIES OF UNIQUE SCHIFF BASE OF BENZIMIDAZOLE DERIVATIVES AS ANTICANCER AGENTS". RASAYAN Journal of Chemistry 16, nr 03 (2023): 1403–15. http://dx.doi.org/10.31788/rjc.2023.1638365.
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Accumulating synthetic pesticides in the living system has brought about several critical alerts from researchers as it interferes with the essential processes in the body. Metal oxide nanoparticles possess suitable properties including band gap and have played an important role in the photocatalytic degradation of toxic chemicals in wastewater and the environment under natural solar radiation. This research aims at the photocatalytic degradation of Type II Pyrethroid Pesticide (Lambda-cyhalothrin) in wastewater and agricultural runoff using Zinc Oxide Nanoparticles. The synthesized ZnO Nanoparticle (NP) was ascertained by characterization using XRD for material crystallinity and crystallite size, SEM, and particle size analysis for surface morphology and size. The EDAX spectra confirmed the presence of Zinc elements and showed that the synthesized zinc oxide nanoparticles were pure. The degradation experiment was conducted under natural solar irradiation. The initial and final/equilibrium concentration of Lambda-cyhalothrin residue were determined using High-performance liquid chromatography (HPLC) followed by computation of degradation capacity. Photocatalytic degradation of LCY was successful following the application of Zinc oxide NPs as nanocatalysts with an efficiency of about 87% as compared to the control. The synthesized Nanoparticle was found to degrade a large percentage of Lambda-cyhalothrin residue in wastewater. Exploiting its application in the remediation of pesticides in agricultural runoff may be crucial at this point.
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Bouafia, Abderrhmane, Salah Eddine Laouini, Abdelaal S. A. Ahmed, Alexander V. Soldatov, Hamed Algarni, Kwok Feng Chong i Gomaa A. M. Ali. "The Recent Progress on Silver Nanoparticles: Synthesis and Electronic Applications". Nanomaterials 11, nr 9 (6.09.2021): 2318. http://dx.doi.org/10.3390/nano11092318.
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Nanoscience enables researchers to develop new and cost-effective nanomaterials for energy, healthcare, and medical applications. Silver nanoparticles (Ag NPs) are currently increasingly synthesized for their superior physicochemical and electronic properties. Good knowledge of these characteristics allows the development of applications in all sensitive and essential fields in the service of humans and the environment. This review aims to summarize the Ag NPs synthesis methods, properties, applications, and future challenges. Generally, Ag NPs can be synthesized using physical, chemical, and biological routes. Due to the great and increasing demand for metal and metal oxide nanoparticles, researchers have invented a new, environmentally friendly, inexpensive synthetic method that replaces other methods with many defects. Studies of Ag NPs have increased after clear and substantial support from governments to develop nanotechnology. Ag NPs are the most widely due to their various potent properties. Thus, this comprehensive review discusses the different synthesis procedures and electronic applications of Ag NPs.
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Siemeling, Ulrich, Frauke Bretthauer, Clemens Bruhn, Tim-Patrick Fellinger, Wah-Leung Tong i Michael C. W. Chan. "Gold Nanoparticles Bearing an α-Lipoic Acid-based Ligand Shell: Synthesis, Model Complexes and Studies Concerning Phosphorescent Platinum(II)-Functionalisation". Zeitschrift für Naturforschung B 65, nr 9 (1.09.2010): 1089–96. http://dx.doi.org/10.1515/znb-2010-0906.
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The surface functionalisation of gold nanoparticles (GNPs) with luminescent platinum complexes has been investigated, utilising α-lipoic acid derivatives for GNP stabilisation. Model complexes have been studied to mimic the chemisorption chemistry required to afford GNPs protected by an α-lipoic acid-based ligand shell with terminal functionalisation suitable for metal coordination, and the unambiguous binding of the cyclic disulfide moiety at a zero-valent precious metal core through oxidative addition has been confirmed by X-ray crystallography. Subsequently, gold nanoparticles bearing the α-lipoic acid-based ligand shell have been prepared and characterised, and a synthetic methodology for the immobilisation of PtII luminophores onto their surface has been established.
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Pushankina, Polina, Mikhail Baryshev i Iliya Petriev. "Synthesis and Study of Palladium Mono- and Bimetallic (with Ag and Pt) Nanoparticles in Catalytic and Membrane Hydrogen Processes". Nanomaterials 12, nr 23 (24.11.2022): 4178. http://dx.doi.org/10.3390/nano12234178.
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A controlled strategy for the electrochemical synthesis of mono- and bimetallic nanoparticles with a unique and complex morphology has been developed. The investigation of the effect of changing the surfactant concentration and current density regulating the medium pH has revealed the fundamental patterns of nanoparticle growth. The developed method has allowed to synthesis of nanoparticles with a controlled pentabranched structure for the monometallic palladium as well as for favorable combinations of metals—Pd-Ag and Pd-Pt. The obtained nanoparticles were investigated in alkaline methanol oxidation. The results demonstrated quite high catalytic activity up to 83.51 mA cm−2 and long-term stability, which are caused by the increase in electrochemically active surface area by increasing the active center’s number. This was made possible due to the creation of unusual nanoparticle morphology, namely the presence of high-energy high-index facets. The developed nanoparticles were also studied as a modifying coating for hydrogen-permeable membranes in the processes of hydrogen transport. The membranes coated with the nanoparticles demonstrated sufficiently high hydrogen flux up to 11.33 mmol s−1 m−2 and high H2/N2 selectivity up to 2254. Such results can be explained by the obvious acceleration of surface processes through the application of the developed nanoparticles. The novel synthesis strategy can potentially be extended to other metal nanoparticle systems. Thus it can be an effective way to solve relevant problems of design of controlled synthetic methods allowing the nanoparticle morphology tuning according to the required functional properties.
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Arshad, Hafiz Muhammad, Amir Shahzad, Sammia Shahid, Sadaqat Ali, Abdul Rauf, Shahzad Sharif, Muhammad Ehsan Ullah, Muhammad Inam Ullah, Muhammad Ali i Hafiz Ishfaq Ahmad. "Synthesis and Biomedical Applications of Zirconium Nanoparticles: Advanced Leaps and Bounds in the Recent Past". BioMed Research International 2022 (13.09.2022): 1–9. http://dx.doi.org/10.1155/2022/4910777.
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Many synthetic routes manufacture zirconium nanoparticles in metal oxide, nitride, and other combination forms. Coupled with other variables such as concentration, pH, and form of precursor used, the various synthetic methods support synthesizing the zirconium metal oxide nanoparticles with changed features. Various synthetic methods were studied, such as sol-gel, hydrothermal, laser ablation, and precipitation. All have different synthetic routes, different precursors and solvents were sued, and the product was characterized by SEM, TEM, photo luminance spectroscopy, UV-absorption spectroscopy, and powder X-ray diffraction. X-ray diffraction determined the crystal structure by identifying the crystal shape, arrangement of atoms, and spacing between them. SEM and TEM studied the particle size and morphology of nanoparticles. UV-visible absorption spectroscopy and PL spectroscopy were used for the determination of optical properties of nanoparticles. Zirconium oxide nanoparticles have many applications in the medical field. The review study primarily focuses on the efficient combination of zirconium dioxide with other additive materials and functionalization techniques used to improve the material’s properties, assisting the use of the material in hip arthroplasty and bone tissue applications. The development of sophisticated near-infrared (NIR) absorbing small molecules for useful phototheranostic applications was discussed in this paper.
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Carrapiço, António, Maria Rosário Martins, Ana Teresa Caldeira, José Mirão i Luís Dias. "Biosynthesis of Metal and Metal Oxide Nanoparticles Using Microbial Cultures: Mechanisms, Antimicrobial Activity and Applications to Cultural Heritage". Microorganisms 11, nr 2 (2.02.2023): 378. http://dx.doi.org/10.3390/microorganisms11020378.
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Nanoparticles (1 to 100 nm) have unique physical and chemical properties, which makes them suitable for application in a vast range of scientific and technological fields. In particular, metal nanoparticle (MNPs) research has been showing promising antimicrobial activities, paving the way for new applications. However, despite some research into their antimicrobial potential, the antimicrobial mechanisms are still not well determined. Nanoparticles’ biosynthesis, using plant extracts or microorganisms, has shown promising results as green alternatives to chemical synthesis; however, the knowledge regarding the mechanisms behind it is neither abundant nor consensual. In this review, findings from studies on the antimicrobial and biosynthesis mechanisms of MNPs were compiled and evidence-based mechanisms proposed. The first revealed the importance of enzymatic disturbance by internalized metal ions, while the second illustrated the role of reducing and negatively charged molecules. Additionally, the main results from recent studies (2018–2022) on the biosynthesis of MNPs using microorganisms were summarized and analyzed, evidencing a prevalence of research on silver nanoparticles synthesized using bacteria aiming toward testing their antimicrobial potential. Finally, a synopsis of studies on MNPs applied to cultural heritage materials showed potential for their future use in preservation.
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Drapak, S. I., A. O. Ivanova-Tolpintseva i Yu B. Khalavka. "Photostimulated Synthesis of Noble Metals Nanoparticles". Chernivtsi University Scientific Herald. Chemistry, nr 819 (2019): 57–83. http://dx.doi.org/10.31861/chem-2019-819-09.
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Nowadays, one of the most relevant areas of modern materials science is the science of nanoparticles and nanomaterials, as well as nanotechnology. Composition, size and shape of nanomaterials at the nanoscale determines its electronic, optical, magnetic, catalytic, etc. properties. Due to the unique optical and catalytic properties, noble metals nanoparticles (silver and gold ones) today are one of the most intensively studied types of nanoobjects. The properties of silver and gold nanoparticles are extremely important and promising for technological use in such areas as electronics, optics, solar energy, information storage, communications, biomedicine, environmental research and others. A number of promising applications of noble metal nanoparticles are due to the effect of localized surface plasmon resonance, which consists in the collective oscillation of conduction electrons relatively to the ions in metallic crystal lattice bounded by the nanoparticle surface at the resonant excitation frequency. The dimensional dependence of the basic physical and chemical properties of nanoparticles makes specific demands on the synthesis, which should provide the necessary particles’ diameter and size distribution, the possibility of surface functionalization, particles’ stability in the manufacturing process, subsequent storage and operation for its further practical application. Existing methods for obtaining noble metals nanoparticles, including physical, thermal, chemical, photochemical, electrochemical, etc. do not provide the required reproducibility or are too expensive for mass use. In addition, most currently known methods allow to obtain metal nanoparticles only with a wide distribution of shapes and sizes. Careful control of the reaction parameters, such as time, process temperature, stirring rate, concentration of reactans and stabilizing additives, allows to narrow the size distribution of nanoparticles, but not always to the desired limits. According to recent studies, monodisperse colloidal solutions of noble metals nanoparticles can be obtained by excitation of plasmon-stimulated reactions in the reaction mixture. This review, based on a rage of experimental studies, demonstrates how light can be used to control the processes of growth, shape and size of noble metals nanoparticles, and to convert heterogeneous populations of metal nanoparticles into populations with high monodispersity. The manifestation of localized surface plasmons in the optical spectra of metal nanoparticles of different sizes and shapes was also considered. In addition, there were also discussed photophysical processes, associated with the excitation of localized surface plasmon resonance in metal nanoparticles, which allow to control chemical reactions at the nanoscale, namely the photothermal effect; concentration of light near the surface of nanoparticles, which leads to an increase in the electromagnetic field and the intensity of the photon flux for molecules near the particles and the generation of hot electron-hole pairs that can participate in charge transfer between nanoparticles and nearby molecules.
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Lavande, Soham, Shraddha Jaiswal, Roshanee Deore, Jayant Pawar i Vidya Tale. "Metal Nanoparticle Synthesis Using Fruit Extracts as Reducing Agents and Comparative Studies with a Chemical Reducing Agent". Biosciences Biotechnology Research Asia 19, nr 2 (30.06.2022): 487–96. http://dx.doi.org/10.13005/bbra/3002.
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Nanoparticle synthesis using plant extracts is biologically safe, cost-effective, and environment-friendly, hence attracting many researchers owing to its advantages over chemical or physical methods. In the current study copper and silver nanoparticles have been synthesized by chemical and biological methods (using fruit extract). The leftover fruits collected from the fruit vendors and were used for the study, such as guava (Psidium guajava L), and tomato (Solanum lycopersicum) as a source of ascorbic acid, while lemon (Citrus limon (L.) Osbeck) and orange (Citrus X sinensis) as a source of citric acid. Quantification of ascorbic acid and citric acid present in fruit extract was performed by Iodometric and acid-base titrations, respectively, followed by Thin Layer Chromatography (TLC) to confirm their role in nanoparticle production. The synthesized nanoparticles were characterized by UV–visible (UV–VIS) spectroscopy and Fourier transform infrared (FT-IR) spectroscopy. The number of particles produced with fruit extract as a reducing agent was more compared to chemical methods. The size and structure of the synthesized nanoparticles produced using fruit extracts were similar to those produced chemically. Also, the antibacterial effect of Cu and Ag nanoparticles was seen against Escherichia coli and Streptococcus pyogenes strains.
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Tsekhmistrenko, S. I., V. S. Bityutskyy, O. S. Tsekhmistrenko, L. P. Horalskyi, N. O. Tymoshok i M. Y. Spivak. "Bacterial synthesis of nanoparticles: A green approach". Biosystems Diversity 28, nr 1 (2.03.2020): 9–17. http://dx.doi.org/10.15421/012002.
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In recent decades, the attention of scientists has been drawn towards nanoparticles (NPs) of metals and metalloids. Traditional methods for the manufacturing of NPs are now being extensively studied. However, disadvantages such as the use of toxic agents and high energy consumption associated with chemical and physical processes impede their continued use in various fields. In this article, we analyse the relevance of the use of living systems and their components for the development of "green" synthesis of nano-objects with exceptional properties and a wide range of applications. The use of nano-biotechnological methods for the synthesis of nanoparticles has the potential of large-scale application and high commercial potential. Bacteria are an extremely convenient target for green nanoparticle synthesis due to their variety and ability to adapt to different environmental conditions. Synthesis of nanoparticles by microorganisms can occur both intracellularly and extracellularly. It is known that individual bacteria are able to bind and concentrate dissolved metal ions and metalloids, thereby detoxifying their environment. There are various bacteria cellular components such as enzymes, proteins, peptides, pigments, which are involved in the formation of nanoparticles. Bio-intensive manufacturing of NPs is environmentally friendly and inexpensive and requires low energy consumption. Some biosynthetic NPs are used as heterogeneous catalysts for environmental restoration, exhibiting higher catalytic efficiency due to their stability and increased biocompatibility. Bacteria used as nanofactories can provide a new approach to the removal of metal or metalloid ions and the production of materials with unique properties. Although a wide range of NPs have been biosynthetic and their synthetic mechanisms have been proposed, some of these mechanisms are not known in detail. This review focuses on the synthesis and catalytic applications of NPs obtained using bacteria. Known mechanisms of bioreduction and prospects for the development of NPs for catalytic applications are discussed.
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Aldosari, F. M., A. M. Azzeer i A. M. Hassib. "Analyzing the Preparation and Properties of Silver Nanoparticles; A Photo-Acoustic Study". Applied Physics Research 10, nr 6 (30.11.2018): 29. http://dx.doi.org/10.5539/apr.v10n6p29.
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Metal nanoparticles have garnered recent attention due to their potential for use in various mechanical, electrical, chemical and optical applications. This study aimed to investigate the synthesis of silver nanoparticles using pulsed photo-acoustic (PA) spectroscopy techniques. The results indicated a linear relationship between absorbance and concentration. Additionally, stability of silver colloids was seen at room temperatures, with no aggregation. The nanoparticles were spherical and between 2-40 nm in diameter. Nanoparticle size and PA signal were inversely proportional. Furthermore, lack of nanoparticle stability was found to weaken the PA signal. Lastly, nanoparticle absorption was inversely proportional to fluorescence. Further studies are needed for exploring the rationale in the relationship between fluorescence and absorption of the nanoparticles.
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Kavitha, P., C. Shanthi i R. Kannan. "Facile green synthesis of Ag, Au, AuAg@C-reduced graphene oxide nanohybrids and its catalytic studies". Digest Journal of Nanomaterials and Biostructures 18, nr 1 (styczeń 2023): 21–29. http://dx.doi.org/10.15251/djnb.2023.181.21.
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Facile green synthesis of gold, silver and silver-gold on graphene oxide nanohybrid using ascorbic acid at room temperature has been studied in this communication. Further the interaction between the metal and graphene oxide was enhanced with the help of the ascorbic acid/dehydroascorbic acid by the calcination process. The ascorbic acid acts as reductant as well as a stabilizer of metal nanoparticles on the support. The micrographs reveal the formation of metal nanoparticles as quantum dots (~ 3-5 nm), results improved catalytic activity towards methylene green degradation in room temperature was studied. The proposed method is facile, fast and eco-friendly for the synthesis of metal nanoparticles over the carbon nanostructures
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Dongil, A. B. "Recent Progress on Transition Metal Nitrides Nanoparticles as Heterogeneous Catalysts". Nanomaterials 9, nr 8 (2.08.2019): 1111. http://dx.doi.org/10.3390/nano9081111.
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This short review aims at providing an overview of the most recent literature regarding transition metal nitrides (TMN) applied in heterogeneous catalysis. These materials have received renewed attention in the last decade due to its potential to substitute noble metals mainly in biomass and energy transformations, the decomposition of ammonia being one of the most studied reactions. The reactions considered in this review are limited to thermal catalysis. However the potential of these materials spreads to other key applications as photo- and electrocatalysis in hydrogen and oxygen evolution reactions. Mono, binary and exceptionally ternary metal nitrides have been synthetized and evaluated as catalysts and, in some cases, promoters are added to the structure in an attempt to improve their catalytic performance. The objective of the latest research is finding new synthesis methods that allow to obtain smaller metal nanoparticles and increase the surface area to improve their activity, selectivity and stability under reaction conditions. After a brief introduction and description of the most employed synthetic methods, the review has been divided in the application of transition metal nitrides in the following reactions: hydrotreatment, oxidation and ammonia synthesis and decomposition.
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Yazdanian, Mohsen, Pouya Rostamzadeh, Mahdi Rahbar, Mostafa Alam, Kamyar Abbasi, Elahe Tahmasebi, Hamid Tebyaniyan, Reza Ranjbar, Alexander Seifalian i Alireza Yazdanian. "The Potential Application of Green-Synthesized Metal Nanoparticles in Dentistry: A Comprehensive Review". Bioinorganic Chemistry and Applications 2022 (3.03.2022): 1–27. http://dx.doi.org/10.1155/2022/2311910.
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Orodental problems have long been managed using herbal medicine. The development of nanoparticle formulations with herbal medicine has now become a breakthrough in dentistry because the synthesis of biogenic metal nanoparticles (MNPs) using plant extracts can address the drawbacks of herbal treatments. Green production of MNPs such as Ag, Au, and Fe nanoparticles enhanced by plant extracts has been proven to be beneficial in managing numerous orodental disorders, even outperforming traditional materials. Nanostructures are utilized in dental advances and diagnostics. Oral disease prevention medicines, prostheses, and tooth implantation all employ nanoparticles. Nanomaterials can also deliver oral fluid or pharmaceuticals, treating oral cancers and providing a high level of oral healthcare. These are also found in toothpaste, mouthwash, and other dental care products. However, there is a lack of understanding about the safety of nanomaterials, necessitating additional study. Many problems, including medication resistance, might be addressed using nanoparticles produced by green synthesis. This study reviews the green synthesis of MNPs applied in dentistry in recent studies (2010–2021).
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AMIENS, C., i B. CHAUDRET. "ORGANOMETALLIC SYNTHESIS OF NANOPARTICLES". Modern Physics Letters B 21, nr 18 (10.08.2007): 1133–41. http://dx.doi.org/10.1142/s0217984907013833.
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Nanoparticles can be synthesized from metal-organic or organometallic precursors, either by classical thermal decomposition, ultrasound activation, photolysis as well as hydrogenation or hydrolysis reactions. The size, size distribution and more importantly surface state of these nanoparticles are much better controlled than when they are produced by chemical or electrochemical reduction of metal salts. Hence, metal or oxide nanoparticles can be obtained that are suitable for fundamental physics at the nanoscale, especially for magnetic studies. This is currently of particular interest as many applications require systems of still smaller sizes, the properties of which are not yet fully understood.
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Gouramma Patil i Sharanabasappa B Patil. "Biological synthesis of Nanoparticles from Medicinal Plants: Recent Studies". International Journal of Research in Pharmaceutical Sciences 12, nr 1 (13.01.2021): 344–49. http://dx.doi.org/10.26452/ijrps.v12i1.4142.
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In a recent trend, nanotechnology has been developed to be an important field of research in various fields like medicinal chemistry, pharmaceuticals and all. On the other hand, compared to chemical method of synthesis, method of synthesis of nanoparticles by green method is simple, effective & ecofriendly. Plant extracts are obtained from the plant, creep, cereals, etc. generally natural extracts are prepared by decoction method or solid powder formation method. The natural extracts are very much effective in the medicinal approach. The study of Nano sized particles towards natural extracts has given a novel way in the field of medicines. So from the nanomaterials of natural extracts, one can expect still good effective results. As we know that preparation of nanoparticles through green approach is one of the good selections in the view of betterment of ecology. Therefore by taking aqueous extracts of medicinal plants’ parts and metal ions, nanoparticles can be synthesized. The plant extract and metal ions are taken in a fixed ratio and keep at room temperature for the reduction. The Changes in the Color confirmed the formation of nanoparticles. Further, the synthesized nanoparticles were characterized by UV, EPMA, XRD and FTIR data.
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Samuel, Melvin S., Saptashwa Datta, Narendhar Chandrasekar, Ramachandran Balaji, Ethiraj Selvarajan i Srikanth Vuppala. "Biogenic Synthesis of Iron Oxide Nanoparticles Using Enterococcus faecalis: Adsorption of Hexavalent Chromium from Aqueous Solution and In Vitro Cytotoxicity Analysis". Nanomaterials 11, nr 12 (3.12.2021): 3290. http://dx.doi.org/10.3390/nano11123290.
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The biological synthesis of nanoparticles is emerging as a potential method for nanoparticle synthesis due to its non-toxicity and simplicity. In the present study, a bacterium resistant to heavy metals was isolated from a metal-contaminated site and we aimed to report the synthesis of Fe3O4 nanoparticles via co-precipitation using bacterial exopolysaccharides (EPS) derived from Enterococcus faecalis_RMSN6 strains. A three-variable Box–Behnken design was used for determining the optimal conditions of the Fe3O4 NPs synthesis process. The synthesized Fe3O4 NPs were thoroughly characterized through multiple analytical techniques such as XRD, UV-Visible spectroscopy, FTIR spectroscopy and finally SEM analysis to understand the surface morphology. Fe3O4 NPs were then probed for the Cr(VI) ion adsorption studies. The important parameters such as optimization of initial concentration of Cr(VI) ions, effects of contact time, pH of the solution and contact time on quantity of Cr(VI) adsorbed were studied in detail. The maximum adsorption capacity of the nanoparticles was found to be 98.03 mg/g. The nanoparticles could retain up to 73% of their efficiency of chromium removal for up to 5 cycles. Additionally, prepared Fe3O4 NPs in the concentration were subjected to cytotoxicity studies using an MTT assay. The investigations using Fe3O4 NPs displayed a substantial dose-dependent effect on the A594 cells. The research elucidates that the Fe3O4 NPs synthesized from EPS of E. faecalis_RMSN6 can be used for the removal of heavy metal contaminants from wastewater.
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Shafey, Asmaa Mohamed El. "Green synthesis of metal and metal oxide nanoparticles from plant leaf extracts and their applications: A review". Green Processing and Synthesis 9, nr 1 (18.06.2020): 304–39. http://dx.doi.org/10.1515/gps-2020-0031.
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AbstractMetal nanoparticles (MNPs) and metal oxide nanoparticles (MONPs) are used in numerous fields. The new nano-based entities are being strongly generated and incorporated into everyday personal care products, cosmetics, medicines, drug delivery, and clothing to impact industrial and manufacturing sectors, which means that nanomaterials commercialization and nano-assisted device will continuously grow. They can be prepared by many methods such as green synthesis and the conventional chemical synthesis methods. Green synthesis includes infinite accession to produce MNPs and MONPs with demanding properties. The structure–function relationships between nanomaterials and key information for life cycle evaluation lead to the production of high execution nanoscale materials that are gentle and environmentally friendly. Majority of plants have features as sustainable and renewable suppliers compared with microbes and enzymes, as they have the ability to pick up almost 75% of the light energy and transform it into chemical energy, contain chemicals like antioxidants and sugars, and play fundamental roles in the manufacture of nanoparticles. Plants considered the main factory for the green synthesis of MNPs and MONPs, and until now, different plant species have been used to study this, but the determined conditions should be taken into consideration to execute this preparation. In this study, we focus on the biosynthesis procedures to synthesize MNPs and MONPs, including comparison between green synthesis and the classical chemistry methods as well as the several new orientation of green synthesis of nanoparticles from different plant parts, especially plant leaf extracts. Plants with reducing compounds is the preferred choice for the synthesis of noble metals – metal ions can be reduced to the corresponding metals in the absence of any other chemicals under microwave irradiation conditions using benign solvent, water. Noble metals such as gold (Au), silver (Ag), platinum (Pt), and palladium (Pd) and other metals such as copper (Cu) and nickel (Ni), which are characterized by their optical, electronic, mechanical, magnetic, and chemical properties, leading to different technological applications. Plants with numerous reducing agents are suitable candidates for the manufacture of noble MNPs. The main purpose of this research is to give a background on green nanotechnology prospective evolution, pertinent concerns appeared related to the green synthesis of metal and metal oxide from plant extracts, nanoparticle formation mechanism, and the importance of flavonoids, vitamin B2, ascorbic acid (vitamin C), and phenolic compounds in the MNP and MONP production. The traditional sorghum beers are produced in many countries in Africa, but diversity in the production process may depend on the geographic localization. These beers are very rich in calories; B-group vitamins including thiamine, folic acid, riboflavin, and nicotinic acid; and essential amino acids such as lysine. However, the Western beers are more attractive than the traditional sorghum beers. The traditional sorghum beers have poor hygienic quality, organoleptic variations, and shorter shelf life compared with the Western beers. Many research studies on traditional sorghum beers have been carried out and documented in several African countries, especially the microbiological and biochemical properties, the technologies used in the manufacture processes, and synthetic characteristics of African traditional sorghum beers (ikigage, merissa, doro, dolo, pito, amgba, and tchoukoutou). The excellent resources for the production of greener biomaterials are plants and considerable advances have been achieved in many fields such as biotechnology and gene transfer. The manufactured biological nanomaterials have a great application in the pharmaceutical industry such as novel pharmaceuticals preparation, drug delivery personification procedures, and production of functional nanodevices.
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Gulia, Khushabu, Abija James, Sadanand Pandey, Kamal Dev, Deepak Kumar i Anuradha Sourirajan. "Bio-Inspired Smart Nanoparticles in Enhanced Cancer Theranostics and Targeted Drug Delivery". Journal of Functional Biomaterials 13, nr 4 (28.10.2022): 207. http://dx.doi.org/10.3390/jfb13040207.
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Globally, a significant portion of deaths are caused by cancer.Compared with traditional treatment, nanotechnology offers new therapeutic options for cancer due to its ability to selectively target and control drug release. Among the various routes of nanoparticle synthesis, plants have gained significant recognition. The tremendous potential of medicinal plants in anticancer treatments calls for a comprehensive review of existing studies on plant-based nanoparticles. The study examined various metallic nanoparticles obtained by green synthesis using medicinal plants. Plants contain biomolecules, secondary metabolites, and coenzymes that facilitate the reduction of metal ions into nanoparticles. These nanoparticles are believed to be potential antioxidants and cancer-fighting agents. This review aims at the futuristic intuitions of biosynthesis and applications of plant-based nanoparticles in cancer theranostics.
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Motshekga, Sarah C., Sreejarani K. Pillai, Suprakas Sinha Ray, Kalala Jalama i Rui W. M. Krause. "Recent Trends in the Microwave-Assisted Synthesis of Metal Oxide Nanoparticles Supported on Carbon Nanotubes and Their Applications". Journal of Nanomaterials 2012 (2012): 1–15. http://dx.doi.org/10.1155/2012/691503.
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The study of coating carbon nanotubes with metal/oxides nanoparticles is now becoming a promising and challenging area of research. To optimize the use of carbon nanotubes in various applications, it is necessary to attach functional groups or other nanostructures to their surface. The combination of the distinctive properties of carbon nanotubes and metal/oxides is expected to be applied in field emission displays, nanoelectronic devices, novel catalysts, and polymer or ceramic reinforcement. The synthesis of these composites is still largely based on conventional techniques, such as wet impregnation followed by chemical reduction of the metal nanoparticle precursors. These techniques based on thermal heating can be time consuming and often lack control of particle size and morphology. Hence, there is interest in microwave technology recently, where using microwaves represents an alternative way of power input into chemical reactions through dielectric heating. This paper covers the synthesis and applications of carbon-nanotube-coated metal/oxides nanoparticles prepared by a microwave-assisted method. The reviewed studies show that the microwave-assisted synthesis of the composites allows processes to be completed within a shorter reaction time with uniform and well-dispersed nanoparticle formation.
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Dubey, Akanksha, i Jayanthi Sivaraman. "Investigating the role of phytochemicals in silver nanoparticle as an antibacterial agent using computational and experimental analysis". Research Journal of Biotechnology 16, nr 12 (25.11.2021): 100–108. http://dx.doi.org/10.25303/1612rjbt100108.
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Designing a powerful approach for the synthesis of metal nanoparticles is a critical footstep in the field of nanotechnology. Algae-mediated synthesis of nanoparticles is a substitute to overthrow the restrictions of traditional methods. Penicillin-binding proteins are proteins binding to β-lactams and are convoluted in cell wall biosynthesis. The present study aimed to investigate the potential role of phytochemicals in inhibiting these penicillin binding proteins against bacterial agents using computational and experimental studies. Biosynthesis of silver nanoparticles was done using aqueous extract of Dictyota bartayresiana and was evaluated for antibacterial activity. Characterization was done via UV-visible spectroscopy, Scanning electron microscopy, Transmission electron microscopy and Xray diffraction studies. It was found that synthesized nanoparticle was spherical in shape and possessed antibacterial property against Staphylococcus aureus and Escherichia coli. Phytochemical screening was performed to identify the chemical constituents present in silver nanoparticles followed by molecular docking studies against penicillin binding proteins found in bacterial strains. In silico designing of silver nanoparticles was done using material science suite followed by probe target interactions. The results displayed a highly stable binding amongst designed nanoparticle and phytochemicals and indicated that the silver nanoparticles possessed antibacterial properties due to phytochemicals present in the extract.
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Popat, Pooja R., Kinjal Nayee, Madhya Patel, Ankit P. Patel, Ruchita J. Patel, Viral A. Patel i Bharat A. Makwana. "Novel Carbidopa Functionalised Silver Nanoparticles a Selective Detection for Lead and Levodopa". Journal of Biomimetics, Biomaterials and Biomedical Engineering 59 (14.02.2023): 21–38. http://dx.doi.org/10.4028/p-5hlj88.
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Novel approaches to engineer nanoparticles with desired chemical characteristics open new opportunities to utilize such materials for assorted applications. In this context, various methods have been developed to prepare metal nanoparticles. In the present work, we report a single-step synthesis method to prepare silver nanoparticles by using Carbidopa which is useful in treating Parkinson's disease to increase the dopamine level of the brain. Here we used the Carbidopa drug as a capping agent. Nanoparticles were characterized by Uv-Visible spectroscopy, Particle size Analyzer (PSA), dynamic light scattering (DLS), Powder X-ray Diffractometry (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Transmission electron microscopy (TEM). Then amino acid detection study was performed with all 24 amino acids, which provides the successful data for sensing the amino acid L-dopa. These prepared nanoparticles were further applied for metal analyte studies which reveal that lead can be sensed successfully by using these nanoparticles. Nanoparticle also shows radical scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH).
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Nechaeva, Olga V., Tatiana A. Shulgina, Ksenia V. Zubova, Elena V. Glinskaya, Natalia V. Bespalova, Nikolay I. Darin, Elena I. Tichomirova i Anna G. Afinogenova. "Antimicrobial activity of aqueous dispersions of silver nanoparticles against pathogens of purulent-inflammatory diseases". Russian Journal of Infection and Immunity 12, nr 4 (9.09.2022): 755–64. http://dx.doi.org/10.15789/2220-7619-aao-1937.
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Currently, metal nanostructures are widely used in medical, microbiological, and veterinary practice. Silver nanoparticles are especially promising as antimicrobial agents, becauseno published data regarding antimicrobial resistance are available. Whiledeveloping preparations based on metal nanoparticles, an important remainingissue is the choice of a stabilizer, introduction of which during the synthesis ensures the preservation of structures at the nanoscale range, and, consequently, relevant main characteristics, including biocidal properties. The object of the study was to investigate silver nanoparticle aqueous dispersions stabilized by natural and synthetic polymeric compounds. Routine strains of Gram-positive and Gram-negative bacteria were used as experimental models: S. aureus 209 P, Escherichia coli ATCC 25922, Proteus mirabilis ATCC 3177 (O-form), Klebsiella pneumoniae ATCC 31488, obtained from the Scientific Centre for Expert Evaluation of Medicinal Products. The antimicrobial activity of diverse variants of silver nanoparticle aqueous dispersions was assessed by serial dilution platingon dense nutrient medium. In this work, we examined no effect of silver nanoparticles without stabilizers, because their absence led to rapid agglomeration of nanostructures and loss of nanoscale characteristics. The highest sensitivity of Gram-positive and Gram-negative bacteria was foundto the action of ansilver nanoparticle aqueous dispersions stabilized by polyazolidinammoniumand modified with iodine hydrate ions. Drug working concentrations ranging from 0.5 to 3% had a bactericidal effect against pathogens of purulent-inflammatory diseases, and the minimum working concentration of 0.125% led to decreased colony-forming units by 2057% for diverse bacterial strains. Silver nanoparticles stabilized with sodium dodecyl sulfate showed high efficiency against the studied test strainsprobably due to the high toxicity of the stabilizer used as was previously established during a comprehensive safety assessment using biotest objects and cell cultures. In this regard, its use as a component of antimicrobial preparations is not preferred. The results of the studies showed that among the variants of silver nanoparticle aqueous dispersions, preparations stabilized with polyvinyl alcohol and polyazolidinammonium modified with iodine hydrate ions are the most promising for use in biomedical practice, because they demonstrate a high level of antibacterial activity against both Gram-positive and Gram-negative bacteria as causative agents of purulent-inflammatory diseases and a low toxicity level. This allows us to recommend them as safe and effective antimicrobial components indisinfectants, as well as antiseptic preparations for prevention and treatment of skin and soft tissue infectious diseases.
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Waychunas, G. A. "Natural nanoparticle structure, properties and reactivity from X-ray studies". Powder Diffraction 24, nr 2 (czerwiec 2009): 89–93. http://dx.doi.org/10.1154/1.3132590.
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Synthetic analogs of naturally occurring nanoparticles have been studied by a range of X-ray techniques to determine their structure and chemistry, and relate these to their novel chemical properties and physical behavior. ZnS nanoparticles, formed in large concentrations naturally bymicrobial action, have an interesting core-shell structure with a highly distorted and strained outer layer. The strain propagates through the particles and produces unusual stiffness but can be relieved by changing the nature of the surface ligand binding. Weaker bound ligands allow high surface distortion, but strongly bound ligands relax this structure and reduce the overall strain. Only small amounts of ligand exchange causes transformations from the strained to the relaxed state. Most remarkably, minor point contacts between strained nanoparticles also relax the strain. Fe oxyhydroxide nanoparticles appear to go through structural transformations dependent on their size and formation conditions, and display a crystallographically oriented form of aggregation at the nanoscale that alters growth kinetics. At least one Fe oxyhydroxide mineral may only be stable on the nanoscale, and nonstoichiometry observed on the hematite surface suggests that for this phase and possibly other natural metal oxides, chemistry may be size dependent. Numerous questions exist on nanominerals formed in acid mine drainage sites and by reactions at interfaces.
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Vasil’kov, Alexander, Margarita Rubina, Alexander Naumkin, Mikhail Buzin, Pavel Dorovatovskii, Georgy Peters i Yan Zubavichus. "Cellulose-Based Hydrogels and Aerogels Embedded with Silver Nanoparticles: Preparation and Characterization". Gels 7, nr 3 (2.07.2021): 82. http://dx.doi.org/10.3390/gels7030082.
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The paper presents the preparation and characterization of novel composite materials based on microcrystalline cellulose (MCC) with silver nanoparticles (Ag NPs) in powder and gel forms. We use a promising synthetic conception to form the novel composite biomaterials. At first MCC was modified with colloidal solution of Ag NPs in isopropyl alcohol prepared via metal vapor synthesis. Then Ag-containing MCC powder was used as precursor for further preparation of the gels. The hydrogels were prepared by dissolving pristine MCC and MCC-based composite at low temperatures in aqueous alkali solution and gelation at elevated temperature. To prepare aerogels the drying in supercritical carbon dioxide was implemented. The as-prepared cellulose composites were characterized in terms of morphology, structure, and phase composition. Since many functional properties, including biological activity, in metal-composites are determined by the nature of the metal-to-polymer matrix interaction, the electronic state of the metal was carefully studied. The studied cellulose-based materials containing biologically active Ag NPs may be of interest for use as wound healing or water-purification materials.
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Prestianni, Lucas, Eric R. Espinal, Sarah F. Hathcock, Nadine Vollmuth, Pixiang Wang, Robert A. Holler, Shaoyang Liu, Brandon J. Kim i Yuping Bao. "Synthesis and Characterization of Quercetin–Iron Complex Nanoparticles for Overcoming Drug Resistance". Pharmaceutics 15, nr 4 (23.03.2023): 1041. http://dx.doi.org/10.3390/pharmaceutics15041041.
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Quercetin, one of the major natural flavonoids, has demonstrated great pharmacological potential as an antioxidant and in overcoming drug resistance. However, its low aqueous solubility and poor stability limit its potential applications. Previous studies suggest that the formation of quercetin-metal complexes could increase quercetin stability and biological activity. In this paper, we systematically investigated the formation of quercetin-iron complex nanoparticles by varying the ligand-to-metal ratios with the goal of increasing the aqueous solubility and stability of quercetin. It was found that quercetin-iron complex nanoparticles could be reproducibly synthesized with several ligand-to-iron ratios at room temperature. The UV-Vis spectra of the nanoparticles indicated that nanoparticle formation greatly increased the stability and solubility of quercetin. Compared to free quercetin, the quercetin-iron complex nanoparticles exhibited enhanced antioxidant activities and elongated effects. Our preliminary cellular evaluation suggests that these nanoparticles had minimal cytotoxicity and could effectively block the efflux pump of cells, indicating their potential for cancer treatment.
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Jahangir, H. Syed, T. Tamil Kumar, M. Mary Concelia i R. Alamelu. "Green Synthesis, Characterization & Antibacterial Studies of Silver (Ag) and Zinc Oxide (Zno) Nanoparticles". Journal of Pure and Applied Microbiology 14, nr 3 (3.09.2020): 1999–2008. http://dx.doi.org/10.22207/jpam.14.3.39.
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Green synthesis nanoparticles were considered as an alternative effective resource instead of chemically engineered metal oxide nanoparticles. Using leaf extracts for green synthesis, essential for the reduction and oxidation process of the metals. Phyllanthus niruri (L.) and Aristolochia indica (L.) leaf extracts were used to synthesize yellowish brown coloured silver (Ag) and white coloured zinc oxide (ZnO) nanoparticles. Synthesized green nanoparticles characterized by different spectroscopic analysis (XRD, XPS, FTIR, PL) and TEM. Characterization results confirmed the particles morphology, size, structure and also their optical and photonic properties. Three different concentrations of Ag and ZnO NPs were analysed against three (gram positive) and five (gram negative) bacteria. Increased levels of green synthesized Ag and ZnO NPs showed increased zone of inhibition than amoxicillin (positive control). Our study proved that the green synthesized Ag and ZnO NPs showed similar unique physical and chemical properties with metal oxide nanoparticles but less toxic while their discharge into the ecosystem.
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Phan, Thi. "The Multifunctional Roles of Chitosan in the Formation of Flower-Shaped Palladium Nanoparticles". Materials Proceedings 3, nr 1 (20.02.2021): 18. http://dx.doi.org/10.3390/iec2m-09256.
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The chemical and physical routes are usually used to synthesize metal nanoparticles. However, the harmful effects on the environment and human health has turned scientists into finding greener methods. We have developed the novel green method for the synthesis of flower Pd nanoparticles based on the chitosan (CS) polymer. In this method, CS can work as a stabilizer, a shape-directing agent, and a size-controllable agent for the synthesis of these nanoparticles. This study provides pioneer evidence about the multifunctional roles of natural polymers in the preparation of metal nanoparticles. Deep and extensive studies should be conducted to explore the great benefits of natural polymers in the green synthesis of metal nanoparticles.
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Li, Yanlin, Jun Ma i Yixing Yuan. "Enhanced Adsorption of Chromium by Stabilized Ca/Al–Fe Layered Double Hydroxide Decorated with Ferric Nanoparticles". Science of Advanced Materials 12, nr 3 (1.03.2020): 441–48. http://dx.doi.org/10.1166/sam.2020.3618.
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Two-dimension magnetic double layer hydroxide nanoparticles (Ca–Al/Fe LDH) were synthesized by the hydrothermal method. Here, we demonstrate a potential method for efficient chromium removal using Ca–Al/Fe LDH as the adsorbent in water treatment. It was found that Cr(VI) could be successfully eliminated using the Ca–Al/Fe LDH. The method achieved extremely fast removal of Cr(VI) from water with high adsorption capacities. As-prepared Ca–Al/Fe LDH had a high specific surface area and anti-agglomeration property, which contributed to preventing nanometer metal particles from conglomerating during the adsorption process. The recycling studies indicated that Ca–Al/Fe LDH exhibited intense chromium absorption in simulated high levels of pollution wastewater. This modified synthetic approach could extend the application of Ca–Al/Fe LDH for heavy metal control by enhancing their adsorption and desorption capacity in wastewater treatment. Furthermore, the modified synthetic method could be used to produce a suite of stabilized, non-toxic chemical magnetic nanoparticles, and could be used for industrial production.
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Mohamad, Nazatul Nabila, Ainorkhilah Mahmood, Nor Aziyah Bakhari, Marlina Mohd Mydin, Norhafiza Mohd Arshad i Norain Isa. "Studies on Surface Plasmon Resonance of Murdannia loriformis Silver Nanoparticles". Journal of Physics: Conference Series 2129, nr 1 (1.12.2021): 012084. http://dx.doi.org/10.1088/1742-6596/2129/1/012084.
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Abstract In this work, surface plasmon resonance (SPR) was investigated over the effect of concentration of metal precursor, concentration of reducing agent, reaction time and pH on formation of silver nanoparticles (AgNPs) using biological method. In this method, Murdannia loriformis extract (MLE) was used as reducing agent and silver nitrate as metal precursor. SPR of Murdania loriformis silver nanoparticles (MLE-AgNPs) was measured through UV-vis spectrophotometer over a range of 380 – 800 nm wavelength. It was found that, as the concentration of MLE, pH and reaction time increases, the SPR peak of MLE-AgNPs at 430 - 490 nm also increases. However, for effect of concentration of metal precursor, the result showed that SPR peak of MLE-AgNPs increases when 1 to 5 mM of silver nitrate was used but decreases for 10 and 15 mM. Significant of this study is to identify the optimum conditions for synthesis of MLE-AgNPs.
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Phuyal, Sitaram, Ganesh Lamichhane, Aakash Gupta, Karan Khadayat, Anup Adhikari, Rishab Marahatha, Sujan Khadka i Niranjan Parajuli. "Biosynthesis of Silver Nanoparticles from Rhododendron arboreum for Metal Sensing, Antibacterial Assessment, and Photocatalytic Degradation". Journal of Nanomaterials 2022 (15.06.2022): 1–12. http://dx.doi.org/10.1155/2022/2110636.
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The nanomaterial industry has focused on green synthetic methods to avoid unpleasant compounds produced during manufacturing, offering eco-friendly, sustainable, and nature-derived alternative methods. In this study, silver nanoparticles (Ag NPs) have been synthesized from an aqueous extract of the leaves of Rhododendron arboreum, where the pH of the reaction mixture is found to be crucial. The reaction progress monitored using the UV-Vis spectrophotometer displayed a strong absorption band at 425 nm at pH 9, suggesting an optimum pH for the synthesis. The Ag NPs thus synthesized were characterized using instrumental techniques. The attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy showed the presence of phytoconstituents in the aqueous extract, which are believed to be responsible for reducing Ag+ ions to Ag NPs and capping agents on its surface for stability. X-ray diffraction (XRD) showed a highly crystalline nature, and energy-dispersive X-ray (EDX) demonstrated the presence of metallic silver. The scanning and transmission electron microscopy (SEM and TEM, respectively) revealed crystalline morphology and monodisperse Ag NPs of sizes ranging from 23 to 41 nm. Furthermore, the metal-sensing activity of biosynthesized Ag NPs was evaluated using various metal ions; they were utilized for highly selective and sensitive colorimetric detection of Hg2+ in an aqueous medium among various metal ion solutions tested with the detection limit of 0.5 mM using the UV-Vis spectrophotometer. Similarly, they were also shown to be effective for the nanocatalytic activity for degradation of methylene blue dye up to 81%. These studies demonstrated Ag NPs as potential candidates for selective detection of mercury in water resources, a tool for sensing the heavy metals and degradation of synthetic dye from industrial effluents in wastewater treatment. Having the high surface-to-volume ratio and size-dependent functionality of Ag NPs, further optimization studies at micromolar and nanomolar detection limits will avail its better industrial utilization. Moreover, biologically mediated Ag NPs can also exhibit good antimicrobial activity against Staphylococcus aureus and Escherichia coli.
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Ponsurya, P., Shahid Hussain, B. H. Abbas Shahul Hameed, R. Perumalsamy, R. Thirumamagal, M. Jayachandran i A. Ayeshamariam. "Studies on Growth Mechanism of Annealed Graphite Powder and Gas-Sensor Applications". Materials Science Forum 832 (listopad 2015): 102–9. http://dx.doi.org/10.4028/www.scientific.net/msf.832.102.
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High quality micro sheet rhombohedral graphite crystals were synthesized by Hummer method using compounds of MWCNT, K2S2O8and P2O5. The growth mechanisms were discussed by finite element simulation. The synthetic sheet rhombohedral graphite crystals showed a higher growth rate in radial direction than that in axial direction. Raman spectrum and Fourier transform infrared spectrum indicated that synthesized sheet rhombohedral Graphite had fewer crystal lattice distortions with no impurities. Finite element simulations indicated that the solvent metal convection field in the radial direction was stronger than that in the axial direction. As prepared graphite powder was annealed at 1350 oC to obtain diamond nanoparticles. The as-prepared products were exposed to formaldehyde gas.
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Jayakrishnan, Priyanga, Sirajunnisa Abdul Razack, Keerthana Sivanesan, Pavithra Sellaperumal, Geethalakshmi Ramakrishnan, Sangeetha Subramanian i Renganathan Sahadevan. "A facile approach towards copper oxide nanoparticles synthesis using Spirulina platensis and assessment of its biological activities". Brazilian Journal of Biological Sciences 5, nr 10 (2018): 433–42. http://dx.doi.org/10.21472/bjbs.051020.
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There is a budding need to develop a method for environmentally benign metal nanoparticle synthesis, that do not use toxic chemicals in the synthesis protocols to avoid adverse effects in medical applications. The present investigation dealt with the synthesis of copper oxide (CuO) nanoparticles from blue green alga, Spirulina platensis. The algal extract consisting of phytochemicals was used as the reducing agent and copper sulphate as the substrate. Synthesised nanoparticles were characterized by UV-Vis spectrophotometry, FT-IR spectroscopy, XRD and SEM. Antibacterial and anticancer activities were assessed for the CuO nanoparticles. The results indicated that the formed CuO nanoparticles were observed to be nanosheets. FT-IR spectral analysis elucidated the occurrence of biomolecules required for the reduction of copper oxide ions. The synthesized nanoparticles were found to be effective at the concentration of 1 mg/mL against Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa and Serratia marcescens. The cytotoxicity activity of CuO nanoparticle was evaluated by MTT Assay against colon cancer cell lines and confirmed that CuO nanoparticle at a concentration of 125 µg/mL had cytotoxic activity. In conclusion, the CuO nanoparticles were synthesized at a low energy supply, in an ecologically safe mode which could be utilized for pharmacological applications and various biotechnological studies.
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Osuntokun, Jejenija, i Peter A. Ajibade. "Structural and Thermal Studies of ZnS and CdS Nanoparticles in Polymer Matrices". Journal of Nanomaterials 2016 (2016): 1–14. http://dx.doi.org/10.1155/2016/3296071.
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We report the synthesis and structural studies of ZnS and CdS nanoparticles in polyvinylpyrrolidone (PVP), poly(vinyl alcohol) (PVA), and poly(methyl methacrylate) (PMMA) matrices. The metal sulfides/polymer nanocomposites were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy, electronic spectroscopy (UV-Vis), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA). The particle sizes as calculated from the absorption spectra were in agreement with the results obtained from TEM and XRD data. They showed metal sulfides nanoparticles in the polymers matrices with average crystallite sizes of 1.5–6.9 nm. The TGA results indicate that incorporation of the nanoparticles significantly altered the thermal properties of the respective polymers with ZnS/PVA and CdS/PVA nanocomposites displaying higher thermal stability than the other polymer nanocomposites.
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Abhilash, Mavinakere Ramesh, Akshatha Gangadhar, Jagadish Krishnegowda, Mahendra Chikkamadaiah i Shivanna Srikantaswamy. "Hydrothermal synthesis, characterization and enhanced photocatalytic activity and toxicity studies of a rhombohedral Fe2O3 nanomaterial". RSC Advances 9, nr 43 (2019): 25158–69. http://dx.doi.org/10.1039/c9ra04978a.
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Tejaswini, G., P. Lakshmi Kishore, V. Naga Lakshmi i K. Bhagya Lakshmi. "A Comprehensive Review on Green Synthetic Approaches and Applications of 3d-Series Metal Oxide Nanoparticles". Asian Journal of Chemistry 34, nr 10 (2022): 2478–88. http://dx.doi.org/10.14233/ajchem.2022.23904.
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Transition metal oxides have been studied by many workers of fields who want to find new ways to use them in medical devices and other fields. Researchers have done a lot of research on solid-state synthesis methods, which require high temperatures and make molecules that are thermodynamically stable. Transition metal oxides have been used for a wide range of things, from nanoparticles that deliver drugs to systems that store information in more than one state. In materials science and technology research and development, a new era of “green synthesis” methods is getting a great attention. Basically, green synthesis of materials and nanomaterials, which is done through a process of regulation, control, cleaning and remediation, will directly help make them more friendly to the environment. In this review, various green approaches for 3d-series metal oxide nanoparticles and their applications are discussed.
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Umarov, A. V. "Study of Thermal Properties of Metal-Filled Nanocompositions Based on Polyethylene". Journal of Nature, Science & Technology 1, nr 4 (21.10.2021): 6–10. http://dx.doi.org/10.36937/janset.2021.004.002.
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The production of metal-containing nanoparticles is one of the important problems of modern science related to the creation of nanomaterials. Nanocomposites based on polymer matrices and uniformly distributed nanoparticles (quantum dots) isolated from each other in them have unique photoluminescent properties; in addition, polymer matrices are convenient stabilizers of nanoparticle growth and have good mechanical properties. Of the nanoparticles of semiconducting materials, metal chalcogenides (CdS, Cu) are of the greatest interest. In the chemical synthesis of metal sulfides in a polymer medium, H2S or a compound containing active sulfur can act as a sulfiding agent. Samples of nanocomposites based on semiconductor sulfides and polyethylene have been synthesized. The composition, structure and structure of nanoparticles were studied by X-ray phase analysis and spectroscopy. Investigated from thermophysical properties. From studies of the temperature dependence of the heat capacity of the compositions, LDPE and CdS compositions, It can be seen that there is a peak on the curve in the temperature range of 100-2250K, which almost degenerates with an increase in the concentration of the filler. Measurements of the temperature dependence of thermal conductivity and heat capacity revealed the presence of reversible structural rearrangements in polymer composites with metal oxide fillers. Moreover, various methods, within the limits of errors, fix a constant transition temperature of electrical conductivity, thermal conductivity and heat capacity, which speaks in favor of the fact that the basis of all detected anomalies is a single mechanism, i.e. structural rearrangement of defect states of polymer composites.
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Navarro, Julien R. G., i Frederic Lerouge. "From gold nanoparticles to luminescent nano-objects: experimental aspects for better gold-chromophore interactions". Nanophotonics 6, nr 1 (6.01.2017): 71–92. http://dx.doi.org/10.1515/nanoph-2015-0143.
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AbstractGold nanoparticles have been the center of interest for scientists since many decades. Within the last 20 years, the research in that field has soared with the possibility to design and study nanoparticles with controlled shapes. From spheres to more complex shapes such as stars, or anisotropic architectures like rods or bipyramids, these new systems feature plasmonic properties making them the tools of choice for studies on light-matter interactions. In that context, fluorescence quenching and enhancement by gold nanostructures is a growing field of research. In this review, we report a non-exhaustive summary of the synthetic modes for various shapes and sizes of isotropic and anisotropic nanoparticles. We then focus on fluorescent studies of these gold nano-objects, either considering “bare” particles (without modifications) or hybrid particles (surface interaction with a chromophore). In the latter case, the well-known metal-enhanced fluorescence (MEF) is more particularly developed; the mechanisms of MEF are discussed in terms of the additional radiative and non-radiative decay rates caused by several parameters such as the vicinity of the chromophore to the metal or the size and shape of the nanostructures.