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1
Mädler, L., W. J. Stark, and S. E. Pratsinis. "Simultaneous deposition of Au nanoparticles during flame synthesis of TiO2 and SiO2." Journal of Materials Research 18, no. 1 (January 2003): 115–20. http://dx.doi.org/10.1557/jmr.2003.0017.
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Nanostructured gold/titania and gold/silica particles with up to 4 wt% Au were made by a single-step process in a spray flame reactor. Gold(III)-chloride hydrate and titania- or silica-based metalorganic precursors were mixed in a liquid fuel solution, keeping concentrations in the flame and overall combustion enthalpy constant. The powders were characterized by x-ray diffraction, transmission electron microscopy, Brunauer–Emmett–Teller, and ultraviolet–visible analysis. The titania or silica specific surface area and the crystalline structure of titania were not affected by the presence of gold in the flame. Furthermore the size of the gold deposits was independent of the metal oxide support (TiO2 or SiO2) and its specific surface area (100 and 320 m2/g, respectively). The gold nanoparticles were nonagglomerated, spherical, mostly single crystalline, and well dispersed on the metal oxide support. Depending on the Au weight fraction (1, 2, and 4 wt%) the Au nanoparticles' mass mean diameter was 3, 7, and 15 nm, respectively, on both titania and silica. The particles showed surface plasmon absorption bands in the ultraviolet–visible region, which is typical for nano-sized gold. This absorption band was red shifted in the case of the titania support, while no shift occurred with the silica support.
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Jiang, Meixia, Qian Li, Xiaowei Cui, Fengjiao Long, Fenglian Ye, Lili Gu, Xianglan Li, and Xiaohua Gong. "Bio-fabricated bioactive arisaema triphyllum aqueous extract-loaded nano-ZnO particles improve the nursing care of esophageal cancer." Materials Express 10, no. 10 (October 31, 2020): 1620–27. http://dx.doi.org/10.1166/mex.2020.1800.
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Metal nanoparticles, synthesized using phyto-constituents, are one of the most economical and environmentally friendly materials. Biogenic zinc oxide nanoparticles (ZnONPs) obtained from Arisaema triphyllum plant extract were synthesized and characterized using UV-visible spectroscopy, XRD, TEM, and EDX. The presence of various plant extracts and the zinc oxide capping of ZnONPs was confirmed using UV-visible spectroscopy, further confirming the existence of ZnO in the 400–430 nm region based on its specific surface plasmon resonance. XRD patterns showed ZnONP-centered cubic crystalline assembly, while electron microscopy showed that the formation of spherical ZnONPs varied from ∼10 nm to 15 nm in diameter. Strong ZnONPs bands were established, as verified by EDX. The anticancer properties of ZnONPs prepared with different extracts were evaluated using esophageal cancer cells. High levels of anticancer activity against the two esophageal cancer cell lines, EC109 and TE8, were observed. The morphological changes of the esophageal cancer cells were evaluated using AO-EB and nuclear staining biochemical methods. Hemolysis assays with human erythrocytes showed excellent bio-compatibility with ZnONPs. To the best of our knowledge, this is the first study to report the use of A. triphyllum-loaded biogenic ZnONPs against esophageal cancer cells.
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Kulriya, P. K., V. N. Singh, D. C. Agarwal, S. Ojha, and D. K. Avasthi. "Localized Surface Plasmon Resonance Studies on Pd/C Nano-Composite System: Effect of Metal Concentration and Annealing Temperature." Journal of Nanoscience and Nanotechnology 20, no. 6 (June 1, 2020): 3859–65. http://dx.doi.org/10.1166/jnn.2020.17508.
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The effects of metal concentration and annealing temperature on the localized surface plasmon resonance (LSPR) properties of the Pd nanoparticles (NP) dispersed in carbon were investigated. The Pd/C nano-composite thin films with 7 to 39 atomic % concentration of metal content were deposited using the atom beam co-sputtering techniques and subjected to annealing at temperature varying from 300 °C to 600 °C. The UV-vis spectroscopy studies on as-prepared films displayed a Mie scattering profile, but not well-defined LSPR bands were observed for all the values of Pd concentration. This is attributed to the smaller size (3–4 nm) of Pd NPs and rough Pd/C interface, as confirmed from TEM studies. When samples were annealed at a temperature of 300 °C, three broad LSPR absorption bands in the visible region, along with a sharp peak at 210 nm, were observed and the effect of Pd concentration variation was insignificant on their position. The multiple LSPR bands were observed due to agglomeration NPs, which is consistent with earlier reports and is also observed in the TEM images. When annealing temperature was subsequently increased to 500 °C, a blue shift in the LSPR peak position with an increase in the Pd concentration was observed, which phenomena is attributed to the formation of bigger NPs with the formation of sharp NPs-interface at high temperature upon annealing. A monotonic increase in the magnitude and decrease in the FWHM with an increase in concentration suggested change in the dielectric function of sample due to the growth of NPs. This is further confirmed from XRD studies, where strain relaxation and grain growth were observed. The intensity of the SPR peak decreased with an increase in the annealing temperature. The LSPR peak disappeared on annealing at a temperature of 600 °C, suggesting the formation of continuous polycrystalline thin films of Pd. In summary, NPs size, metalmatrix interface, and concentration of metal play key roles in the tailoring the LSPR properties of the Pd.
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Proença, Manuela, Marco S. Rodrigues, Joel Borges, and Filipe Vaz. "Gas Sensing with Nanoplasmonic Thin Films Composed of Nanoparticles (Au, Ag) Dispersed in a CuO Matrix." Coatings 9, no. 5 (May 25, 2019): 337. http://dx.doi.org/10.3390/coatings9050337.
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Magnetron sputtered nanocomposite thin films composed of monometallic Au and Ag, and bimetallic Au-Ag nanoparticles, dispersed in a CuO matrix, were prepared, characterized, and tested, which aimed to find suitable nano-plasmonic platforms capable of detecting the presence of gas molecules. The Localized Surface Plasmon Resonance phenomenon, LSPR, induced by the morphological changes of the nanoparticles (size, shape, and distribution), and promoted by the thermal annealing of the films, was used to tailor the sensitivity to the gas molecules. Results showed that the monometallic films, Au:CuO and Ag:CuO, present LSPR bands at ~719 and ~393 nm, respectively, while the bimetallic Au-Ag:CuO film has two LSPR bands, which suggests the presence of two noble metal phases. Through transmittance-LSPR measurements, the bimetallic films revealed to have the highest sensitivity to the refractive index changes, as well as high signal-to-noise ratios, respond consistently to the presence of a test gas.
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Vasiljevic, Natasa, Vinicius Cruz San Martin, and Andrei Sarua. "Electrodeposition of Plasmonic Nanostructures." ECS Meeting Abstracts MA2022-02, no. 23 (October 9, 2022): 985. http://dx.doi.org/10.1149/ma2022-0223985mtgabs.
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Electrochemical control and the use of electrodeposition in the design of dynamic plasmonics have attracted much attention in recent years.1 Development of dynamic plasmonic metamaterials is attractive for many applications such as molecular sensing and analysis, environmental monitoring, photo-catalysis, colour changing displays and electrochromic devices such as 'smart' windows. Electrodeposition is one of the most attractive ways to create and reversibly transform nanostructures' shape, size and chemical composition.2,3 Plasmonics is related to the localised surface excitations of electrons in metal nanostructures due to strong interactions with light. The resulted electric field enhancement due to the surface plasmons can be used to manipulate light–matter. Nanostructured Ag and Au are classic plasmonic materials. While silver is a metal that exhibits many advantages over gold, such as higher extinction coefficients in the blue and UV region of the EM spectrum, sharper extinction bands and extremely high field enhancements, its employment is hindered by low chemical stability. The most recent theoretical analysis suggests that Au-Ag derived nanostructures with controlled geometry, composition, and distribution can create new interesting optical phenomena.4 By developing Au-Ag based nanostructures, we can then benefit from combining optical properties of Au and Ag and, at the same time, improve the chemical stability of silver. We investigated the electrodeposition of Au and Ag-based arrays of ordered and random nano-particles on indium tin oxide substrates from different solutions and studied their optical properties. We demonstrated that varying the electrodeposition parameters led to changes in both the resonance wavelength and the strength of resonance linked to the structural characteristics (size and shape) and the chemical composition of the deposited particles. Exploration of the dynamic reversible changes via electrodeposition will be presented. References: Y. Jin, L. Zhou, J. Liang, and J. Zhu, Adv. Photon., 3(4), 044002 (2021). G. Wang, X. Chen, S. Liu, C. Wong, S. Chu, ACS Nano, 10 (2), 1788–1794, (2016) C. J. Barile, D. J. Slotcavage, J. Hou, M. T. Strand, T. S. Hernandez, M. D. McGehee, Joule 1 (1), 133-145 (2017) G. Guisbiers, R. Mendoza-Cruz, L. Bazan-Diaz, J. J. Velazquez-Salazar, R. Mendoza-Perez, J. A. Robledo-Torres, J. L. Rodriguez-Lopez, J. M. Montejano-Carrizales, R. L. Whetten, Jose-Yacaman, M. ACS Nano, 10(1), 188-198, (2016)
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Ismail, Eman, Aliyah Saqer, Eman Assirey, Arshi Naqvi, and Rawda Okasha. "Successful Green Synthesis of Gold Nanoparticles using a Corchorus olitorius Extract and Their Antiproliferative Effect in Cancer Cells." International Journal of Molecular Sciences 19, no. 9 (September 3, 2018): 2612. http://dx.doi.org/10.3390/ijms19092612.
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A facile bottom-up “green” synthetic route of gold nanoparticles (Au NPs) is described, using a leaf extract of the Malvaceae plant Corchorus olitorius as a reducing and stabilizing agent. The size and shape of the obtained nanoparticles were modulated by varying the amounts of the metal salt and the broth extract in the reaction medium. Only one hour was required for the complete conversion to Au NPs, suggesting that the reaction rate was higher or comparable to those of nanoparticles synthesized by chemical methods. The obtained nanoparticles were characterized by UV–visible spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, and thermal gravimetric analysis (TGA). While infrared spectroscopy was employed to characterize the various functional groups in the organic layer that stabilized the particles, TEM images were used to optimize the conditions for NPs growth. A low concentration of the C. olitorius extract yielded mixed triangular and hexagonal shapes; in contrast, quasi-spherical shapes of Au NPs with an average size of 37–50 nm were obtained at a higher extract broth concentration. The Au NPs displayed Surface Plasmon Resonance (SPR) bands at 535 nm. An in vitro cytotoxic assay of the biocompatible Au NPs revealed a strong cytotoxic activity in three human cancer cell lines, namely, colon carcinoma HCT-116, hepatocellular carcinoma HepG-2, and breast adenocarcinoma MCF-7. In-silico bioactivity, drug-likeness, and ADMET (Absorption, Distribution, Metabolism, Excretion, and Toxicity) predictions were conducted in order to examine the pharmacokinetic behavior of the compounds present in the C. olitorius extract.
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Shubina, T. V., D. S. Plotnikov, A. Vasson, J. Leymarie, M. Larsson, P. O. Holtz, B. Monemar, Hai Lu, W. J. Schaff, and P. S. Kop’ev. "Surface-plasmon resonances in indium nitride with metal-enriched nano-particles." Journal of Crystal Growth 288, no. 2 (March 2006): 230–35. http://dx.doi.org/10.1016/j.jcrysgro.2005.12.003.
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Fedorenko, L. "Self-Organization Processes of Nanostructure Formation by Laser Radiation in Metal." Advanced Materials Research 222 (April 2011): 18–23. http://dx.doi.org/10.4028/www.scientific.net/amr.222.18.
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The current state of knowledge about mechanisms of metal nano-particles (NP) formation processes induced by the interaction of high-energy laser beam with surface of the metallic lattices (Au, Ag, Cu) is presented. The review includes an evaluation of the contribution of self-organized effects into the processes of the metal nano-structurization depending on the laser mode, external factors and internal parameters of an active zone. It was noticed that intensive pulsed laser illumination enabled to stimulate nano-fragmentation at the fluencies near and above the melting threshold of the metal in different mediums The laser induced processes of metallic particles formation by ablation of the metal target with consequent NP sizes stabilization by precise temperature tuning in the active zone, local plasmon resonance in liquids, and microablation mechanism in metal films in the conditions of surface plasmon resonance (SPR) due to self-organization effects are considered. Comparative analysis of the laser nano-technologies in air, vacuum, rarefied gas and liquid environments showed the advantages of self-organization in NP generation processes based on the SPR effects and their perspectives.
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Nonaka, Shigehiko, Koichi Kawajiri, Hirokazu Yasuba, Takuya Sugiyama, and Stefan T. Ivanov. "Novel Optical Surface Plasmon Propagating along a Planar Metal with Nano-Dielectric Particles." Japanese Journal of Applied Physics 41, Part 1, No. 7B (July 30, 2002): 4798–801. http://dx.doi.org/10.1143/jjap.41.4798.
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Li, Jin, Haoru Wang, Zhi Li, Zhengcheng Su, and Yue Zhu. "Preparation and Application of Metal Nanoparticals Elaborated Fiber Sensors." Sensors 20, no. 18 (September 10, 2020): 5155. http://dx.doi.org/10.3390/s20185155.
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In recent years, surface plasmon resonance devices (SPR, or named plamonics) have attracted much more attention because of their great prospects in breaking through the optical diffraction limit and developing new photons and sensing devices. At the same time, the combination of SPR and optical fiber promotes the development of the compact micro-probes with high-performance and the integration of fiber and planar waveguide. Different from the long-range SPR of planar metal nano-films, the local-SPR (LSPR) effect can be excited by incident light on the surface of nano-scaled metal particles, resulting in local enhanced light field, i.e., optical hot spot. Metal nano-particles-modified optical fiber LSPR sensor has high sensitivity and compact structure, which can realize the real-time monitoring of physical parameters, environmental parameters (temperature, humidity), and biochemical molecules (pH value, gas-liquid concentration, protein molecules, viruses). In this paper, both fabrication and application of the metal nano-particles modified optical fiber LSPR sensor probe are reviewed, and its future development is predicted.
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Kumar, Kuldeep, and P. Arun. "SPR in Cesium Halide Thin Films Due to Embedded Elliptic Cesium Metal Nano-Particles." Ukrainian Journal of Physics 63, no. 9 (September 24, 2018): 824. http://dx.doi.org/10.15407/ujpe63.9.824.
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Cesium nanorods embedded in cesium halides (CsCl, CsBr, and CsI) show surface plasmon resonance (SPR) absorption peaks. The size and shape of these cesium nanorods in the cesium halide matrix evolve with time, which gives some uncontrollable data for comparing with the theory. The theory used here was developed by R. Gans. It leads to the good match between experiment and theory for Cs–Cs halide nanocomposites.
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Pandhurnekar, Chandrashekhar, Himani Pandhurnekar, and Avinash Bharati. "A Minireview on the Applications of Nanobiosensors Based on Localized Surface Plasmon Resonance Phenomenon." Journal of ISAS 1, no. 2 (October 31, 2022): 22–34. http://dx.doi.org/10.59143/isas.jisas.1.2/hzdp9030.
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In this new era of nano-materials, most chemists and physicists are familiar with the phenomenon of localized surface plasmon resonance (SPR). Noble-metal nano-particles with dimensions (3–100 nm) much smaller than the wavelength of incident light (400–900 nm) exhibit this tendency. In nanostructured materials, due to their very small particle size, the electrons are restricted within the nanoparticle surface area and oscillate with a certain frequency. It is noteworthy that the phenomenon of localized surface plasmon resonance appears when the frequency of the incoming photons overlaps with the frequency of the electrons. As this oscillation of surface electrons is taking place against the restoring forces of the positive nuclei, there is a formation of plasmon resonance. This characteristic property of scattering and absorption of photons appearing in the SPR of every nano-structured material, make them excellent nanoprobes for a variety of applications such as cell imaging and detection of protein phosphorylation and many others. The performance of bio-chemical sensing devices has been greatly improved by the development of localized surface plasmon resonance (SPR) based sensors. In the present minireview, we have briefly discussed the classification of biosensors and the basics of their instrumentation. Some of these applications have been discussed here using some nano-engineered biosensors.
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Pandhurnekar, Chandrashekhar, Himani Pandhurnekar, and Avinash Bharati. "A Minireview on The Applications of Nanobiosensors Based on Localized Surface Plasmon Resonance." Journal of ISAS 1, no. 2 (October 31, 2022): 22–34. http://dx.doi.org/10.59143/isas.jisas.1.2.zbbi9491.
Full textAbstract:
In this new era of nano-materials, most chemists and physicists are familiar with the phenomenon of localized surface plasmon resonance (SPR). Noble-metal nano-particles with dimensions (3–100 nm) much smaller than the wavelength of incident light (400–900 nm) exhibit this tendency. In nanostructured materials, due to their very small particle size, the electrons are restricted within the nanoparticle surface area and oscillate with a certain frequency. It is noteworthy that the phenomenon of localized surface plasmon resonance appears when the frequency of the incoming photons overlaps with the frequency of the electrons. As this oscillation of surface electrons is taking place against the restoring forces of the positive nuclei, there is a formation of plasmon resonance. This characteristic property of scattering and absorption of photons appearing in the SPR of every nano-structured material, make them excellent nanoprobes for a variety of applications such as cell imaging and detection of protein phosphorylation and many others. The performance of bio-chemical sensing devices has been greatly improved by the development of localized surface plasmon resonance (SPR) based sensors. In the present minireview, we have briefly discussed the classification of biosensors and the basics of their instrumentation. Some of these applications have been discussed here using some nano-engineered biosensors.
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Pandhurnekar, Chandrashekhar, Himani Pandhurnekar, and Avinash Bharati. "A Minireview on the Applications of Nanobiosensors Based on Localized Surface Plasmon Resonance Phenomenon." Journal of ISAS 1, no. 2 (October 31, 2022): 22–34. http://dx.doi.org/10.59143/isas.jisas.1.2.hzdp9030.
Full textAbstract:
In this new era of nano-materials, most chemists and physicists are familiar with the phenomenon of localized surface plasmon resonance (SPR). Noble-metal nano-particles with dimensions (3–100 nm) much smaller than the wavelength of incident light (400–900 nm) exhibit this tendency. In nanostructured materials, due to their very small particle size, the electrons are restricted within the nanoparticle surface area and oscillate with a certain frequency. It is noteworthy that the phenomenon of localized surface plasmon resonance appears when the frequency of the incoming photons overlaps with the frequency of the electrons. As this oscillation of surface electrons is taking place against the restoring forces of the positive nuclei, there is a formation of plasmon resonance. This characteristic property of scattering and absorption of photons appearing in the SPR of every nano-structured material, make them excellent nanoprobes for a variety of applications such as cell imaging and detection of protein phosphorylation and many others. The performance of bio-chemical sensing devices has been greatly improved by the development of localized surface plasmon resonance (SPR) based sensors. In the present minireview, we have briefly discussed the classification of biosensors and the basics of their instrumentation. Some of these applications have been discussed here using some nano-engineered biosensors.
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Daoudi, Chouaib, Mahmoud Ould Metidji, Mohamed Remram, Anne-Marie Jurdyc, Matteo Martini, Hélène Gehan, and Dominique Vouagner. "Nano-assembling and optical properties of sub-100 nm raspberry-like nanoparticles." European Physical Journal Applied Physics 82, no. 2 (May 2018): 20401. http://dx.doi.org/10.1051/epjap/2018180065.
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The optical properties of sub-100 nm raspberry-like nano-systems composed of highly monodisperse silica particles and large gold nanoparticles (GNPs) is studied experimentally. The nanoparticles (NPs) were prepared by a self-assembly method, and the pH of each solution was determined by measuring the ζ-potential to ensure the stability of the nano-systems. Dynamic light scattering measurements show a narrow size distribution of NPs, and fairly dispersed particles in solution. The obtained nanoraspberries was also studied by transmission electron microscopy, which shows that the GNPs closely packed on the surface of silica particles. This effect induced a broadening and a shift of the absorption band to higher wavelengths, with an increase in GNPs density. It was also observed that the reduced size of silica particles resulted in a shortening of the inter-particles distance, which has favoured the generation of many hot spots in the gaps between GNPs. The tenability of obtained plasmon bands may have benefits in SERS probe, photocatalysis and fluorescence-based bioimaging.
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Lee, Hoon, and Seung-Ki Lee. "Formation of metal nano particles on optical fiber for fiber optic localized surface plasmon resonance sensor." Journal of Sensor Science and Technology 17, no. 2 (March 31, 2008): 95–99. http://dx.doi.org/10.5369/jsst.2008.17.2.095.
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ISHIGURO, Atsushi, Yasuyuki MORITA, and Yang JU. "514 Study on efficiency enhancement of solar cell with local surface plasmon resonance usine metal nano particles." Proceedings of Autumn Conference of Tohoku Branch 2012.48 (2012): 172–73. http://dx.doi.org/10.1299/jsmetohoku.2012.48.172.
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Praveena, V. Durga, and K. Vijaya Kumar. "Physicochemical Studies on Nano Silver Particles Prepared by Green and Chemical Methods." Advanced Materials Research 938 (June 2014): 242–50. http://dx.doi.org/10.4028/www.scientific.net/amr.938.242.
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AgNPs were synthesized by two different methods chemically using sodium citrate as reducing agent, plant mediated by achyranthes aspera as reducing agent. Chitosan (CS) biopolymer is used as a capping agent in order to enhance the stability and dispersibility as well as to remove aggregation. The appearance of surface Plasmon band in the ultraviolet-visible spectra (410-445 nm) is due to the formation of AgNPs in different sizes. Also the data was clarified that the CS molecules coordinate to the surface of nanoAg particles through their head-groups. FTIR spectra were recorded in a Perkin Elmer version 10.03.06, Spectro Photometer. The FTIR analysis suggests that the prepared chitosan silver nanocomposite film consists of an intermediate/or complex of tri-ammonium citrate, chitosan and metal ions. Finally Antibacterial activity of Ag-CS composites indicating that highest antibacterial activity was detected with green film than chemical film.
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Shaik, Shakira, Lwamkelekile Mkize, Mthokozisi Khumalo, and Nisha Singh. "GREEN SYNTHESIS OF NANO-SILVER PARTICLES FROM LEAF AND STEM EXTRACTS OF IBOZA (TETRADENIA RIPARIA)." African Journal of Traditional, Complementary and Alternative Medicines 12, no. 6 (September 21, 2015): 33–38. http://dx.doi.org/10.21010/ajtcam.v12i6.5.
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Background: Secondary metabolites derived from plant extracts can be used in the reduction of metal salts into their respective nanoparticles using
simple, environmentally friendly and cost effective green synthesis techniques. Metal nanoparticles have important applications in medicine and
agriculture. The leaves of Tetradenia riparia (Iboza), an important medicinal species in South Africa, are reported to contain various terpenoids and
pyrones which can be used in the reduction of silver nitrate (AgNO3) to nano-silver particles.
Materials and Methods: Fresh leaves and stems of Iboza were oven-dried, crushed, extracted in water and methanol and filtered followed by
incubation with AgNO3. Synthesized nano-silver particles were characterised using ultraviolet visible (UV-Vis) spectroscopy, scanning electron
microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy and Fourier transform infrared (FTIR) spectroscopy.
Results: The bio-reduction of metal ion to base metal was rapidly conducted in a single step and at room temperature and pressure. UV-Vis spectra
showed the characteristic surface plasmon resonance band of the synthesized nano-silver particles at 410 nm for all extracts. SEM analysis revealed
predominantly aggregated spherically-shaped nano-silver particles with a size range of 20-50 nm and an average diameter of 26 nm. The presence of
elemental silver in the nanoparticles was confirmed by EDX at 3 keV. As revealed by FTIR analysis, the reducing agents included terpenoids and
pyrones which were responsible for reducing and capping the nano-silver particles.
Conclusion: Both methanol and aqueous-derived extracts of Iboza leaves and stems can be used to synthesize nano-silver particles. FTIR evidence
suggests that the reduction of the silver ions and the synthesis of the nanoparticles may have been actioned by various terpenoid and pyrone
compounds found in the plant parts.
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Koh, Seok Keun, Jung Hwan Lee, Charles Lee, and Katherine Koh. "Nano-Scale Particle Formation by Dynamic Mixing Method in Physical Vapor Deposition." Key Engineering Materials 708 (September 2016): 14–19. http://dx.doi.org/10.4028/www.scientific.net/kem.708.14.
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Nano size (2 - 10 nm) metal particles were formed and accumulated on powder substrate by conventional physical vapor deposition (PVD) process, in which the powder were a non-volatile in vacuum, such as Al2O3 powder. The neutral nuclei which were formed on the substrates from vaporized or sputtered metal atoms at an initial thin film growth were not grown up to coalescence and island stage with arrival atoms and ad-atom migration in the continuous deposition process, when the powder in vessel were continuously stirred during the deposition. Nano sized particles on the polymer chips (diameter: 1-2mm) easily dispersed into the polymer matrix by heating the chips, and on non-soluble powder, g-Al2O3, were stuck on the supporters stably in air. The nanoparticles on sucrose directly formed colloid with water solvents without dispersive agents. Most of the nano sized particles appear their own characteristic colors due to plasmon effect. Concentration and size of the nanoparticles are controlled by physical parameters in the PVD and the stirring speed of the powder. Surface phenomena on the substrate have been discussed with TEM, SEM, EDX, UV spectroscopy, etc. comparing with the conventional thin film growth.
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Bai, Chunyan, Jiqing Lian, Xiangcai Ma, Peizhen Qiu, Dileep Kumar, and Saima Kanwal. "Particle Trapping Properties of Metal Annular Slits under Vector Field Excitation." Photonics 10, no. 4 (April 13, 2023): 445. http://dx.doi.org/10.3390/photonics10040445.
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This article presents the particle capture performance of annular slits, which offer a simple alternative to complex micro/nano structures used to excite and focus surface plasmon polaritons (SPPs). Additionally, the annular slits are compatible with a variety of vector light fields, generating diverse SPP field distributions under their excitation. These SPP fields can be regulated by varying the vector light field parameters, thereby offering the annular slit structure the ability to flexibly capture and manipulate particles. The rotation and movement of captured objects can be achieved by changing the position and phase difference of the incident beams with linear polarization. Different material and sized metallic particles can be stably captured with a radially polarized beam excitation due to the strong convergence. These capabilities are demonstrated by evaluating the optical force and trapping potential based on the finite difference time domain (FDTD) simulation. This study provides valuable insights into the practical application of annular slits for particle capture and manipulation.
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Xiong, Lin, Yutao Li, Minwoo Jung, Carlos Forsythe, Shuai Zhang, Alexander S. McLeod, Yinan Dong, et al. "Programmable Bloch polaritons in graphene." Science Advances 7, no. 19 (May 2021): eabe8087. http://dx.doi.org/10.1126/sciadv.abe8087.
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Efficient control of photons is enabled by hybridizing light with matter. The resulting light-matter quasi-particles can be readily programmed by manipulating either their photonic or matter constituents. Here, we hybridized infrared photons with graphene Dirac electrons to form surface plasmon polaritons (SPPs) and uncovered a previously unexplored means to control SPPs in structures with periodically modulated carrier density. In these periodic structures, common SPPs with continuous dispersion are transformed into Bloch polaritons with attendant discrete bands separated by bandgaps. We explored directional Bloch polaritons and steered their propagation by dialing the proper gate voltage. Fourier analysis of the near-field images corroborates that this on-demand nano-optics functionality is rooted in the polaritonic band structure. Our programmable polaritonic platform paves the way for the much-sought benefits of on-the-chip photonic circuits.
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Zhao, Xiaoyu, Wei Xu, Xiuxia Tang, Jiahong Wen, and Yaxin Wang. "Design of Ag/TiO2/Ag Composite Nano-Array Structure with Adjustable SERS-Activity." Materials 15, no. 20 (October 19, 2022): 7311. http://dx.doi.org/10.3390/ma15207311.
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How to fabricate large area controllable surface-enhanced Raman scattering (SERS) active nanostructure substrates has always been one of the important issues in the development of nanostructure devices. In this paper, nano-etching technology and magnetron sputtering technology are combined to prepare nanostructure substrate with evolvable structure, and Ag/TiO2/Ag composites are introduced into the evolvable composite structure. The activity of SERS is further enhanced by the combination of TiO2 and Ag and the electron transfer characteristics of TiO2 itself. Deposition, plasma etching, and transfer are carried out on self-assembled 200 nm polystyrene (PS) colloidal sphere arrays. Due to the shadow effect between colloidal spheres and the size of metal particles introduced by deposition, a series of Ag/TiO2/Ag nanostructure arrays with adjustable nanostructure substrates such as nano-cap (NC), nano cap-star (NCS), and nano particle-disk (NPD) can be obtained. These nanoarrays with rough surfaces and different evolutionary structures can uninterruptedly regulate optical plasmon resonance and reconstruct SERS hotspots over a large range, which has potential application value in surface science, chemical detection, nanometer photonics, and so on.
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Kluczyk, K., C. David, J. Jacak, and W. Jacak. "On Modeling of Plasmon-Induced Enhancement of the Efficiency of Solar Cells Modified by Metallic Nano-Particles." Nanomaterials 9, no. 1 (December 20, 2018): 3. http://dx.doi.org/10.3390/nano9010003.
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We demonstrate that the direct application of numerical packets like Comsol to plasmonic effect in solar cells metallically modified in nano-scale may be strongly inaccurate if quantum corrections are neglected. The near-field coupling of surface plasmons in metallic nanoparticles deposited on the top of a solar cell with band electrons in a semiconductor substrate strongly enhances the damping of plasmons in metallic components, which is not accounted for in standard numerical packets using the Drude type dielectric function for metal (taken from measurements in bulk or in thin layers) as the prerequisite for the numerical e-m field calculus. Inclusion of the proper corrections to plasmon damping causes additional enhancement of the plasmon-induced photo-effect efficiency growth of a metalized photo-diode by ten percent, at least, in comparison to only effect induced by the electric field concentration near metallic nanoparticles. This happens to be consistent with the experimental observations which cannot be explained by only local increases of the electrical field near the curvature of metallic nanoparticles determined by a finite-element solution of the Maxwell–Fresnel boundary problem as given by a numerical system like Comsol. The proper damping rate for plasmons can be identified by application of the Fermi Golden Rule approach to the plasmon-band electron coupling. We demonstrate this effect including the material and size dependence in two types of solar cells, multi-crystalline Si and CIGS (copper-indium-gallium-diselenide) as idealized photo-diode semiconductor substrate modified by various metallic nano-particles, in comparison to the experimental data and Comsol simulation.
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Hsieh, Li-Zen, Yuan-Fong Chou Chau, Chee Ming Lim, Mo-Hua Lin, Hung Ji Huang, Chun-Ting Lin, and Md Idris Muhammad Nur Syafi’ie. "Metal nano-particles sizing by thermal annealing for the enhancement of surface plasmon effects in thin-film solar cells application." Optics Communications 370 (July 2016): 85–90. http://dx.doi.org/10.1016/j.optcom.2016.03.009.
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Mahmoud, Essam R. I., Hamad Almohamadi, Abdulrahman Aljabri, Sohaib Z. Khan, Ahmad N. Saquib, Mohammed Farhan, and Mohammed Abdel-Ghani Elkotb. "Fabrication and Characterization of Steel-Base Metal Matrix Composites Reinforced by Yttria Nanoparticles through Friction Stir Processing." Materials 14, no. 24 (December 10, 2021): 7611. http://dx.doi.org/10.3390/ma14247611.
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Friction Stir Processing (FSP) was used to fabricate metal matrix composite, based on steel and reinforced with nano-sized yttrium oxide powder. The powder was packed in a narrow longitudinal groove of 2 mm depth and 1 mm width cut in the steel plate’s rear surface. Different rotation speeds of 500–1500 rpm were used, at a fixed traveling speed of 50 mm·min−1. Single-pass and two passes, with the same conditions, were applied. The direction of the second pass was opposite to that of the first pass. After the first pass, complete nugget zones were obtained when the rotation speeds were more than 700 rpm with some particles agglomeration. The added particles showed as narrow elliptical bands, with a band pitch equal to the rotation speed over traveling speed. Performing the second FSP pass in the opposite direction resulted in better particles distributions. Almost defect-free composite materials, with homogenously distributed yttria nano-sized particles, were obtained after two passes when rotation speeds more than 700 rpm were used. The resulting steel matrix grains were refined from ~60 μm of the base metal to less than 3 μm of the processed nugget zone matrix. The hardness and the tensile strength of the fabricated materials improved almost two-fold over the base metal. Uniform microhardness values within the nugget areas were observed at higher rotational speeds. The ductility and toughness of the fabricated composites were reduced compared to the base metal.
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Badoni, P. P., Goutam Kumar, Mahender Singh, Navneet Singh, Arun K. Khajuria, Bharti, and Sanjay Dutt. "Geranium wallichianum Leaf Extract Mediated Synthesis of Silver Nanoparticles: Characterization and its Antimicrobial Activity." Asian Journal of Chemistry 31, no. 5 (March 28, 2019): 1128–32. http://dx.doi.org/10.14233/ajchem.2019.21916.
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In present study, the Geranium wallichianum leaf extract (aqueous) and 1 mM silver nitrate solution (aqueous) were amalgamated to synthesize silver particles within the nanometer range. Initial colour changes and surface-plasmon-resonance (SPR) absorbance band observed in UV-visible spectroscopic study gave support to configuration of silver nano-particles. Silver nanoparticles were characterized by XRD, TEM and FTIR spectroscopy. Then antimicrobial (antibacterial and antifungal) activities of silver nanoparticles against selected microbial strains were studied by well diffusion method. During this work, silver SPR absorption bands between 405-425 nm range were shown by Geranium wallichianum leaf extract mediated synthesized silver nanoparticles sample solutions at different intervals. X-ray diffraction pattern displayed the formation of face centred cubic phase silver nano-structures. TEM measurements confirmed that silver nanoparticles are spherically shaped and maximum particles in 9-16 nm size range having average diameter 12.5 nm. Important FT-IR peaks at 3314.11, 1710.60, 1587.11 and 1347.77 cm-1 were predicted for hydroxyl, carbonyls, unsaturated C-C bonds and phenolic groups respectively. Further from antimicrobial results, it has been found that values of diameter of zone of inhibition (mm) of synthesized silver nanoparticles against B. subtilis, S. aureus, L. plantarum, P. aeruginosa, A. niger and C. albicans strains were 32, 28, 25, 25 35 and not active, respectively. MIC-MLC (μL) values were also determined. At last, it can be concluded that antimicrobial agents of 9-16 nm size range and stabilized by polyhydroxy-bioactive-components present in extract, in the form of silver nanoparticles has been productively synthesized.
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Ahmed, Mohammed Muqtader, Farhat Fatima, Md Khalid Anwer, Saad M. Alshahrani, Ahmed Alalaiwe, and Prakash Katakam. "Biosynthesis, characterization and anti-microbial activity of silver nanoparticle based gel hand wash." Green Processing and Synthesis 8, no. 1 (January 28, 2019): 577–83. http://dx.doi.org/10.1515/gps-2019-0027.
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Abstract In the current study, silver nanoparticles (AgNPs) were biosynthesised by microwave irradiation using Azadirachta indica. The formation of AgNPs was confirmed by surface plasmon resonance (SPR) band at 408 nm at UV-visible spectroscopy due to reduction of silver metal into (AgNPs) and further confirmed its particles in nano range. Nine different smart-gel hand wash were prepared by dispersing (AgNPs) in the HPMC and/or Pluronic F-127 polymers. The prepared smart gel hand wash was optimized based on pH, viscosity, spreadability, foamability, clarity. The optimized hand wash (NH5) had pH (6.6 ± 0.33), viscosity (66 ± 0.77, cp), spreadability (24.34 g-cm/s), foamability (100 mL). The optimized hand wash (NH5) showed a superior efficacy against pathogenic organisms in comparison to germ protection based marketed hand wash.
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Ciracì, Cristian, Radoslaw Jurga, Muhammad Khalid, and Fabio Della Sala. "Plasmonic quantum effects on single-emitter strong coupling." Nanophotonics 8, no. 10 (August 14, 2019): 1821–33. http://dx.doi.org/10.1515/nanoph-2019-0199.
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AbstractCoupling between electromagnetic cavity fields and fluorescent molecules or quantum emitters can be strongly enhanced by reducing the cavity mode volume. Plasmonic structures allow light confinement down to volumes that are only a few cubic nanometers. At such length scales, nonlocal and quantum tunneling effects are expected to influence the emitter interaction with the surface plasmon modes, which unavoidably requires going beyond classical models to accurately describe the electron response at the metal surface. In this context, the quantum hydrodynamic theory (QHT) has emerged as an efficient tool to probe nonlocal and quantum effects in metallic nanostructures. Here, we apply state-of-the-art QHT to investigate the quantum effects on strong coupling of a dipole emitter placed at nanometer distances from metallic particles. A comparison with conventional local response approximation (LRA) and Thomas-Fermi hydrodynamic theory results shows the importance of quantum effects on the plasmon-emitter coupling. The QHT predicts qualitative deviation from LRA in the weak coupling regime that leads to quantitative differences in the strong coupling regime. In nano-gap systems, the inclusion of quantum broadening leads to the existence of an optimal gap size for Rabi splitting that minimizes the requirements on the emitter oscillator strength.
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Dmitruk, N., T. Barlas, A. Dmytruk, A. Korovin, and V. Romanyuk. "Synthesis of 1D Regular Arrays of Gold Nanoparticles and Modeling of Their Optical Properties." Journal of Nanoscience and Nanotechnology 8, no. 2 (February 1, 2008): 564–71. http://dx.doi.org/10.1166/jnn.2008.a137.
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Self-organized formation of uniform coating of semiconductor substrate by metal nanoparticles offers a convenient and efficient access to large-scale arrays of uniform metal-semiconductor nanostructures. We used a cheap and facile method of photoinduced chemical gold deposition from an aqueous or alcohol gold salt solution onto semiconductor surface (GaAs, InP). By controlling of both the solution composition and the deposition conditions, gold particles of 10–50 nm in diameter were obtained and the gold covering degree of the semiconductor surface was varied in a wide range. Morphology of the nano/micro structures formed was characterized by atomic force microscopy and scanned electron microscopy with local element analysis. The investigations show that the semiconductor surface patterning can be used for the selective deposition of gold nanoparticles, because they are located predominantly at the tops of the microrelief. We have used specially textured by the anisotropic chemical etching microrelief surfaces of semiconductor single crystal as templates and have obtained nanoparticle arrays in the shape of 1D systems of near parallel quasiperiodical wires. For the periodic 1D array of metal nanowires built into the air-semiconductor interface the spectral and angular dependencies of the transmittance/reflectance of the polarized light have been obtained theoretically using differential formalism. These dependencies demonstrate non-monotonic behaviour at surface plasmon polariton excitation conditions and show possibility of designing functional subwavelength devices.
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Kim, Bo-Myung, M. Siva Pratap Reddy, Young-Woong Lee, and Chinho Park. "Enhanced surface and optical properties of colloidal silver nano-particles on GaN-based light-emitting diodes by a localized surface plasmon resonance effect using a low-cost metal-assisted chemical etching method." Optics Communications 450 (November 2019): 276–81. http://dx.doi.org/10.1016/j.optcom.2019.06.023.
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Ali, A., M. A. Ashraf, Q. A. Minhas, Q. A. Naqvi, M. A. Baqir, and P. K. Choudhury. "On the Core-Shell Nanoparticle in Fractional Dimensional Space." Materials 13, no. 10 (May 22, 2020): 2400. http://dx.doi.org/10.3390/ma13102400.
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The investigation of core-shell nanoparticles has been greatly exciting in biomedical applications, as this remains of prime importance in targeted drug delivery, sensing, etc. In the present work, the polarizability and scattering features of nanoparticles comprised of nano-sized dielectric/metallic core-shell structures were investigated in the fractional dimensional (FD) space, which essentially relates to the confinement of charged particles. For this purpose, three different kinds of metals—namely aluminum, gold and silver—were considered to form the shell, having a common silicon dioxide (SiO2) nanoparticle as the core. It is noteworthy that the use of noble metal-SiO2 mediums interface remains ideal to realize surface plasmon resonance. The core-shell nanoparticles were considered to have dimensions smaller than the operating wavelength. Under such conditions, the analyses of polarizability and the scattering and absorption cross-sections, and also, the extinction coefficients were taken up under Rayleigh scattering mechanism, emphasizing the effects of a varying FD parameter. Apart from these, the tuning of resonance peaks and the magnitude of surface plasmons due to FD space parameter were also analyzed. It was found that the increase of FD space parameter generally results in blue-shifts in the resonance peaks. Apart from this, the usage of gold and silver shells brings in fairly large shifts in the peak positions of wavelengths, which allows them to be more suitable for a biosensing purpose.
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Ugo, Cataldi, and Buergi Thomas. "Plasmonic coupling induced by growing processes of metal nanoparticles in wrinkled structures and driven by mechanical strain applied to a polidimethisiloxisilane template." Photonics Letters of Poland 9, no. 2 (July 1, 2017): 45. http://dx.doi.org/10.4302/plp.v9i2.702.
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We report the mechanical control of plasmonic coupling between gold nanoparticles (GNPs) coated onto a large area wrinkled surface of an elastomeric template. Self-assembly and bottom-up procedures, were used to fabricate the sample and to increase the size of GNPs by exploiting the reduction of HAuCl4 with hydroxylamine. The elastic properties of template, the increase of nanostructure size joined with the particular grating configuration of the surface have been exploited to trigger and handle the coupling processes between the nanoparticles. Full Text: PDF ReferencesG. Mie, "Beiträge zur Optik trüber Medien, speziell kolloidaler Metallösungen", Ann. Phys. 25, 377 (1908) CrossRef U. Kreibig and M. Vollmer, Optical properties of metal cluster, Berlin 1995 CrossRef S. A. Maier, Plasmonics: Fundamentals and Applications, Springer, New York, 2007 CrossRef L. A. Lane, X. Qian, and S. Nie, "SERS Nanoparticles in Medicine: From Label-Free Detection to Spectroscopic Tagging", Chem. 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Roper, "Gold Nanoparticle Polydimethylsiloxane Thin Films Enhance Thermoplasmonic Dissipation by Internal Reflection", J. Phys. Chem. 118, 7523-7531 (2014) CrossRef Y. Jin, "Engineering Plasmonic Gold Nanostructures and Metamaterials for Biosensing and Nanomedicine", Adv. Mater. 24, 5153-5165 (2012) CrossRef J. H. Lee, Q. Wu, and W. Park, "Metal nanocluster metamaterial fabricated by the colloidal self-assembly", Optics Letters 34, Issue 4, 443-445 (2009) CrossRef R. Pratibha, K. Park, I. I. Smalyukh, and W. Park, "Tunable optical metamaterial based on liquid crystal-gold nanosphere composite", Optics Express 17, Issue 22, 19459-19469 (2009) CrossRef J. Dintinger, S. Mühlig, C. Rockstuhl, and T. Scharf, "A bottom-up approach to fabricate optical metamaterials by self-assembled metallic nanoparticles", Optical Materials Express 2, Issue 3, 269-278 (2012) CrossRef T. Maurer, J. Marae-Djouda, U. Cataldi, A. G., Guillaume Montay, Y. Madi, B. Panicaud, D. Macias, P.-M. Adam, G. Léveque, T. 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Buergi, "Growing gold nanoparticles on a flexible substrate to enable simple mechanical control of their plasmonic coupling", Journal of Materials Chemistry C 2(37), 7927-7933 (2014). CrossRef S. K. Ghosh and T. Pal, "Interparticle Coupling Effect on the Surface Plasmon Resonance of Gold Nanoparticles: From Theory to Applications", Chem. Rev. 107, 4797 (2007) CrossRef M. K. Kinnan and G. Chumanov, "Plasmon Coupling in Two-Dimensional Arrays of Silver Nanoparticles: II. Effect of the Particle Size and Interparticle Distance", J. Phys. Chem. C 114, 7496 (2010) CrossRef X. L. Zhu, S. S. Xiao, L. Shi, X. H. Liu, J. Zi, O. Hansen and N. A. Mortensen, "A stretch-tunable plasmonic structure with a polarization-dependent response", Opt. Express, 20, 5237 (2012) CrossRef K. H. Su, Q. H. Wei, X. Zhang, J. J. Mock, D. R. Smith and S. Schultz, "Interparticle Coupling Effects on Plasmon Resonances of Nanogold Particles", Nano Lett. 3, 1087 (2003) CrossRef Y. L. Chiang, C. W. Chen, C. H. Wang, C. 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BAZYLYAK, Liliya, Andriy KYTSYA, Pavlo LYUTYI, Orest KUNTYI, Alla PROKOPALO, and Olena KARPENKO. "SYNTHESIS AND ANTIMICROBIAL ACTIVITY OF COLLOIDAL SOLUTIONS OF BICOMPONENT Ag/CuO NANOPARTICLES STABILIZED BY RAMNOLIPID." Proceedings of the Shevchenko Scientific Society. Series Сhemical Sciences 2022, no. 70 (September 30, 2022): 159–68. http://dx.doi.org/10.37827/ntsh.chem.2022.70.159.
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Despite the extremely high activity of researchers in the direction of green synthesis of nano-particles of silver, copper, as well as bimetallic nanoparticles Ag/Cu-NPs, the many aspects of the synthesis of nanoparticles based on silver and copper remain unexplored, in particular, the studies on the influence of the nature of biosurfactants on the characteristics are relevant obtained nano¬particles, in particular their size, shape, etc., as well as the influence of the morphology and compo¬sition of nanoparticles on their antimicrobial properties. Therefore, the purpose of this work was to synthesize colloidal solutions of bicomponent Ag/CuO-NPs nanoparticles of different composition and to investigate their antimicrobial activity. Bicomponent Ag/CuO nanoparticles of different composition were obtained by the method of coprecipitation of Ag+ and Cu2+ cations in solution of rhamnolipid. It was found that the process of formation of monocomponent CuO nanoparticles is completed within 2.5 hours but the reduction of silver ions in aqueous solutions of RL occurs within a few minutes. The obtained Ag/CuO-NPs were studied using UV-visible spectroscopy and the method of powder diffraction of X-rays. It was found that the absorption spectra of Ag/CuO-NPs solutions are characterized by two maxima at 280 and 410 nm, which correspond to the surface plasmon resonance bands of CuO and Ag-NPs, res-pectively. Based on the obtained data, it is reasonable to assume that the obtained Ag/CuO-NPs can form core-shell structures in which the role of the core will be played by silver surrounded by a CuO shell. Taking into account the prospects of using the nanoparticles based on silver and copper as antimicrobial agents for the plant protection, the antimicrobial activity of the synthesized Ag/CuO-NPs was investigated. The gram-negative bacteria-phytopathogens were used as test microorganisms, namely Agrobacterium tumefaciens, which is the causative agent of crown gall disease of a wide range of agricultural crops and Xanthomonas campestris, which is the causative agent of the "black rot" disease in cruciferous vegetables. The antimicrobial activity of the synthesized colloidal solutions of Ag/CuO was evaluated by the minimum inhibitory concentration values. The results of the studies of antimicrobial activity of the synthesized Ag/CuO colloidal solutions showed that the obtained preparations effectively inhibit the growth of phytopathogenic bacteria Agrobacterium tumefaciens and Xanthomonas campestris and it was found that the obtained drugs are more active against the Xanthomonas campestris.
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Rismaningsih, Nurmanita, Hiroki Yamauchi, Tatsuya Kameyama, Hiroshi Yukawa, Yoshinobu Baba, Taro Uematsu, Susumu Kuwabata, and Tsukasa Torimoto. "Controlling Electronic Energy Structure of Near-IR-Responsive Ag(In,Ga)(S,Se)2 Quantum Dots for In Vivo Bioimaging." ECS Meeting Abstracts MA2022-01, no. 13 (July 7, 2022): 935. http://dx.doi.org/10.1149/ma2022-0113935mtgabs.
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[Introduction] Since cancer is a leading cause of death worldwide, early diagnostic and treatment observation using biosensors becomes urgent. To date, the development of the biosensors is limited to the utilization of fluorescent probes such as organic dyes or fluorescent proteins, which suffer from various weakness[1]. Therefore, new probes that are more photostable than current organic fluorophores are needed. Semiconductor called quantum dots (QDs) of a few nanometers in size exhibit unique photochemical properties different from their bulk materials, owing to the quantum size effect. Binary QDs composed of group II−VI or IV−VI semiconductors, such as CdS, CdSe, and PbS, have been intensively investigated because of intense PL, high quantum yield, resistance to photo-bleaching, and broad excitation with narrow emission bands, which made them ideal for high contrast optical imaging of biological systems. However, notable toxicity associated with Cd and Pb causes serious limitations in practical use. Recently, mixed-cation QDs, such as ZnAgInS[2], AgInGaS[3], and AgInGaSe[4], have been an environmentally friendly alternative to conventional binary QDs. Their photochemical properties were controlled through the composition of QDs as well as their particle size. Controlling the composition of QDs containing multinary chalcogen elements, that is, mixed-anion QDs, is also expected to be another strategy to tune their physicochemical properties, but the method to prepare such QDs showing intense PL has not been developed well. In this study, we report the strategy to prepare Ag(In, Ga)(S, Se)2 (AIGSSe) QDs, of tunable photochemical properties, such as energy gap (Eg) and photoluminescence peak, with the ratio of Se/S in the particles. [Experimental] AIGSSe QDs were synthesized by a solution-phase synthesis method. A mixture of AgOAc, In(acac)3, and Ga(acac)3 was used as a metal ion precursor, and that of thiourea and selenourea was used as a chalcogen precursor. These were added to a test tube with a mixture solvent of oleylamine and dodecane thiol, in which the ratio of Se/(Se+S) varied from 0 to 1.0. The solution was heated at 100~250 °C, and then formed QDs were isolated by adding methanol. The resulting wet precipitates were washed several times with ethanol, followed by dissolving in chloroform. Thus-obtained AIGSSe QDs were surface-coated by GaSx shell to improve PL property. Furthermore, these QDs were incorporated into unilamellar liposomes of 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) to make them dissolved in aqueous solution before being injected into the back of a mouse, and their PL intensity was measured. [Results and Discussion] The absorption onset was red-shifted from 580 nm to 830 nm with an increase in the Se/(S+Se) ratio in preparation, indicating that the Eg of QDs was decreased from 1.9 to 1.5 eV with an increase in the Se/(Se+S) ratio from 0 to 1.0 in QDs. Thus-obtained AIGSSe QDs exhibited broad PL peaks with relatively weak intensities. However, the surface coating of AIGSSe QDs with GaSx shell (AIGSSe@GaSx) remarkably enhanced the intensity of PL peak. The PL quantum yield (QY) of AIGSSe QDs varied in the range of 2~43%, but QDs with each Se/(S+Se) ratio exhibited increased QY after surface coating with GaSx shell. Especially, AIGSSe@GaSx with Se/(S+Se) = 0 had the highest QY value as much as 50%. The PL peak wavelength was red-shifted from 580 nm to 785 nm with a decrease in the Eg of AIGSSe core, the FWHM of PL peak being varied in the range of 0.147 ~ 0.357 eV. TEM measurement revealed that the AIGSSe@GaSx QDs were spherical, and their average size was almost constant at ca. 4 nm with narrow size distribution, regardless of Se/(Se+S) in preparation. AIGSSe@GaSx QDs with Se/(Se+S) = 0.50 exhibited a sharp PL peak at 785 nm in first biological window, which was suitable for in vivo imaging. These QDs were encapsulated with DSPC liposomes so that the QDs were dispersed in aqueous solution. Thus-obtained AIGSSe@GaSx QD-DSPC liposomes maintained a sharp band-edge PL peak even in an aqueous dispersion, in which the PLQY was slightly decreased from 25% in chloroform to 21% in aqueous dispersions but was high enough to be used as a near-IR PL probe. We successfully detected PL emission from the QDs through the skin of a mouse, and the PL intensity was proportional to the concentration of injected QDs. [References] [1] T. Jin, et al., J Mater Chem B, 2020, 8, 10686. [2] T. Kameyama, et al., J. Phys. Chem. C, 2018, 122, 13705. [3] T. Kameyama, et al., ACS Appl. Mater. Interfaces, 2018, 10, 42844. [4] T. Kameyama, et al., ACS Appl. Nano Mater., 2020, 3, 3275.
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dos Santos, Sidney, Ricardo de Couto, Ingrid da Silva, Marcia Regina Aouada, Vera Costantino, Luiz da Costa, and Gustavo Perotti. "Production of Silver Nanoparticles Mediated by Aqueous Extracts of Tucumã (Astrocaryum aculeatum) Pulp." Journal of the Brazilian Chemical Society, 2023. http://dx.doi.org/10.21577/0103-5053.20220141.
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Tucumã (Astrocaryum aculeatum) pulp presents a large number of secondary metabolites that can mediate the synthesis of metallic nanoparticles through a greener and more sustainable synthetic route than traditional ones. This study investigated the production of silver nanoparticles (AgNPs) mediated by aqueous extracts of tucumã pulp assessing different parameters, such as temperature, concentration of extract, and pH values of the reaction media. The alkaline reaction media produced the most intense and well-defined bands around 400 nm in the electronic spectra, indicating the formation of AgNPs in the three concentrations of tucumã pulp evaluated. The increase in the temperature of the reaction media also enhanced the surface plasmon resonance band of AgNPs but it increased the polydispersivity of produced nanoparticles according to the dynamic light scattering (DLS) and transmission electron microscopy (TEM) data. Zeta potential results indicated moderate stability of the AgNPs (close to -30 mV). Antimicrobial assessment of the colloidal metal particles indicated microbicide activity against the Gram-negative Escherichia coli bacterium.
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Dubey, Shivangi, Kuldeep Kumar, and Palakkandy Arun. "Surface Plasmon Resonance in Metal Nano-spheres Explained with LCR Circuits." Physical Chemistry Chemical Physics, 2023. http://dx.doi.org/10.1039/d3cp00589e.
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The manuscript details various simple LCR circuits to explain the experimentally observed Surface Plasmon Resonance behavior of spherical metal nano-particles. The results of the circuit’s performance simulated using standard software...
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Anderson, R. B., J. Fisher, A. Hor, A. Lu, H. Paudel, K. Bayat, M. Baroughi, T.-S. Luk, P. S. May, and S. Smith. "Spectroscopic Imaging of Metal-Enhanced Upconversion on Plasmonic Substrates." MRS Proceedings 1457 (2012). http://dx.doi.org/10.1557/opl.2012.1522.
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ABSTRACTWe use spectroscopic imaging to investigate the enhancement of infra-red to visible upconversion in rare-earth doped nano-particles (NaYF4:Yb:Er) supported on nano-fabricated plasmonic substrates consisting of square lattices of Au nano-pillars fabricated by electron beam lithography and designed to support a surface plasmon polariton at frequencies which are nearresonant with the rare-earth ion (Yb3+) absorption. We observe a systematic enhancement in the efficiency of upconversion associated with the interaction of the co-doped nano-particles with the plasmonic substrate. Spectrally-resolved imaging provides a massively parallel means of assessing the range of achievable enhancement and its relation to the specific configuration of the substrate / upconverting nano-particle system. Spectrally-resolved reflectivity of the plasmonic substrates confirms the role of the surface plasmon polariton in the upconversion enhancement. Experimental results are compared to Finite Difference Time Domain simulations of the frequency-dependent reflectivity of these metallic nanostructures.
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Dawi, E. A., E. Mustafa, and T. Siahaan. "Anisotropic deformation of colloidal particles under 4 MeV Cu ions irradiation." Materials Research Express, August 8, 2022. http://dx.doi.org/10.1088/2053-1591/ac87ef.
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Abstract Anisotropic deformation of colloidal particles was investigated under ion irradiation with 4 MeV Cu ions. In this study, 0.5 µm-diameter colloidal silica particles, 0.5 µm-diameter Au-silica core-shell particles, and 15 nm-diameter Au colloids embedding in a planar Si/SiO2 matrix were irradiated with 4 MeV Cu ions at room temperature and normal incidence. In colloidal silica particles, ion beam irradiation causes dramatic anisotropic deformation; silica expands perpendicular to the beam and contracts parallel, whereas Au cores elongate. Au colloids in a planar SiO2 matrix were anisotropically transformed from spherical colloids to elongated nanorods by irradiating them with 4 MeV Cu ions. The degree of anisotropy varied with ion flux. Upon irradiating the embedded Au colloids, dark-field light scattering experiments revealed a distinct color shift to yellow, which indicates a shift in surface plasmon resonance. A surface plasmon resonance measurement reveals the plasmon resonance bands are split along the arrays of Au colloids. Our measurements have revealed resonance shifts that extend into the near-infrared spectrum by as much as 50 nm.
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Lekshmy, O., K. S. Beena Kumari, and R. Sudha Devi. "Ecofriendly Synthesis and Characterization of Magnesium based Metal - Organic Frame Work." Journal of Surface Science and Technology, February 15, 2023, 203–9. http://dx.doi.org/10.18311/jsst/2021/28590.
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Magnesium based metal - organic Framework (MOF) was synthesized by using Benzene Di-Carboxylic acid (BDC), MgSO4.7H2O and a flower extract of Clitoria ternatea. The prepared MOF was characterized by FTIR spectrum, SEM-EDS, XRD, DLS and PL Spectrum. The crystalline nature of the synthesized MOF was revealed in XRD patterns. The nano particle nature of the MOF was confirmed from the SEM pictures. FT-IR spectra showed a peak at 520cm-1 designated characteristic absorption bands of synthesized Mg-MOF nano particles. The zeta potential value showed that the surface charge of the synthesized MOF is neutral and hence disperse in solution without having any tendency for agglomeration and coagulation on standing. The photoluminescence spectra indicated luminescent nature and hence this nano crystalline MOF finds very good application as luminescent material and as sensing material.
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Hamed, Mohammed S. G., Y. A. Ahmed Abdallah, and Genene Tessema Mola. "Suppressing charge recombination in disordered polymers blend medium." Journal of Physics D: Applied Physics, June 27, 2023. http://dx.doi.org/10.1088/1361-6463/ace1ff.
Full textAbstract:
Abstract Charge recombination is one of the critical factors that influence the performance of thin film polymer solar cells (TFPSC). In this investigation metal, plasmonic nano-particles are employed to suppress charge recombination and energy loss in TFPSC. Trimetallic nano-composite was successfully synthesized, composed of copper, nickel, and silver (Cu/Ni/Ag) using wet chemistry. The nano-composite was incorporated into polymer based solar absorber layers at different concentrations. The absorber layer is a fullerene-based bulk-heterojunction design using poly-3-hexylthiophene (P3HT) donor polymer. The results show that the power conversion efficiency (PCE) of the device doped with nano-composite has improved by 85% compared to the undoped one. The incorporation of tri-metallic nano-composite into the polymer blend solar absorber resulted in enhanced optical absorption and improved collection of photo-current as reflected by recorded high short circuit current density (Jsc) and fill factor (FF). The enhancement of the performance is due to the occurrence of local surface plasmon resonances in polymer medium. The experiment indicated that there is some increment in an open circuit voltage, which is attributed to the low energy losses as the result of improved exciton dissociation, charge carrier transport, and collection.
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Aseel I. Mahmood, Shehab A. Kadhim, Nadia F. Mohammed, and Intisar A. Naseef. "Simulation design of silver nanoparticle coated photonic crystal fiber sensor based on surface plasmon resonance." Experimental and Theoretical NANOTECHNOLOGY, January 15, 2021, 57–64. http://dx.doi.org/10.56053/5.1.57.
Full textAbstract:
Surface Plasmon Resonance (SPR) is the charge density excitation oscillation (surface Plasmon’s, (SP)) caused by the polarized light along with the metal-dielectric interface by agreeing to phase-matching condition between polarized light and SPR. SPR method has unusual advantages like label-free, real-time and high resolutions with less than 10-7 RIU which is not consenting with other sensing methods. Photonic Crystal Fiber (PCF) presents unique features like design elasticity, geometric flexible and extraordinary guiding mechanism which head for better performance contrast conventional optical fibre, Additionally, the presence of air holes gives the possibility to insert multi able materials, that can recognize the interaction of travelling light and materials operatively. Adding the advantages of PCF to the properties of SPR, lead to design very strong and unique devices in different applications. In this paper, the PCF sensor based on SPR technique had been presented. The inner holes of PCF were coated with silver and then filled with air and ethanol. This was achieved theoretically by Finite Element Method (FEM). When the phase-matching condition was achieved at a fixed wavelength, the energy of the core-guided mode is shifted to the plasmon area and a resonant loss peak is observed at this wavelength. The simulated results show that a blue shifting is obtained when the outer air holes of PCF is filling with ethanol while the inner ring is filled with silver nano-particles. The maximum resolution and sensitivity are 5.66*10-4 RIU, 132.3 nm/RIU respectively in the sensing range of air refractive index to ethanol refractive index are obtained. The submitted design could be very useful in many fields like refractive index and temperature sensing applications.
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Zidane, Younes, Salah E. Laouini, Abderrhmane Bouafia, Souhaila Meneceur, Mohammed L. Tedjani, Sohad A. Alshareef, Hanadi A. Almukhlifi, et al. "Green synthesis of multifunctional MgO@AgO/Ag2O nanocomposite for photocatalytic degradation of methylene blue and toluidine blue." Frontiers in Chemistry 10 (December 15, 2022). http://dx.doi.org/10.3389/fchem.2022.1083596.
Full textAbstract:
Introduction: In this paper, MgO@AgO/Ag2O nanoparticles were greenly synthesized, the current idea is to replace the harmful chemical technique with an ecofriendly synthesis of metal oxide nanoparticles (NPs) utilizing biogenic sources.Methods: The current investigation was conducted to create silver oxide NPs decorated by MgO NPs (namely, MgO@AgO/Ag2O nanocom-posite) using the leaves extract of Purslane (Portulaca Oleracea) as the reducing and capping agent. The nanopowder was investigated by means of X-ray diffraction, scanning electron mi-croscope, BET surface area, Fourier transform infrared, and UV-vis spectrophotom-eter studies. XRD studies reveal the monophasic nature of these highly crystalline silver nano-particles. SEM studies the shape and morphology of the synthesis AgO/Ag2O and MgO@AgO/Ag2O NPs. The presence of magnesium and oxygen was further confirmed by EDS profile.Results and discussion: The surface area was found to be 9.1787 m2/g and 7.7166 m2/g, respectively. FTIR analysis showed the presence of specific functional groups. UV-vis spectrophotometer studies show the absorption band at 450 nm due to surface plasmon resonance. The results have also indicated the high performance of the greenly synthesized AgO/Ag2O NPs and MgO@AgO/Ag2O NPs for photocatalytic activity dye degradation (methylene blue and toluidine blue).
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Rogachev, A. A. "Nucleation, first growth stages and structure of nano-sized polymer coatings deposited from active gas phase." Nanotechnology : the development , application - XXI Century, 2021. http://dx.doi.org/10.18127/j22250999-201901-02.
Full textAbstract:
This paper presents an analysis of the structural-morphological, kinetic patterns of the initial growth stages of single-component and composite (polymer-polymer and metal-polymer) nanoscale coatings based on the products of electron-beam dispersion of polymers. The main features of the deposition processes from the active gas phase occurring on the substrate surface and the established size dependences of the structure and molecular composition are explained on the basis of the adsorption-polymerization mechanism for the formation of coatings. It was established that among the most important features of the deposition process from the active gas phase is the simultaneous flow of polymerization and structure formation of adsorbed molecular fragments of the polymer under the conditions of exposure of the active components of the plasma, dispersive filler, and the substrate surface. This feature has a decisive influence on the nucleation of polymer particles, the molecular structure and morphology of nanoscale layers, as well as the dependence of their properties on thickness. Using the PTFE and PE coatings, it was shown that the orientation and ordering of the formed layers changes during the coating growth: at the initial stages of deposition in the layer up to 150 nm, the molecules are oriented predominantly parallel, and in thicker layers due to the bulk structure formation perpendicularly substrate surface. When deposited on the surface subjected to plasma treatment, the growth rate of the formed coating at the initial stages of growth increases by more than 5 times. At the same time, such layers contain predominantly linear molecules with a relatively lower molecular weight. The introduction of micro-and nanoscale polymer coatings in the process of their growth of the formed silver or copper nanoclusters leads to the formation of highly oriented, continuous, highly dispersed layers already at the initial stages of growth. The orientation of the macromolecules of the matrix with the maintenance of Ag or Cu nanoclusters in it has parameters characteristic of single-component coatings. In PTFE+Mo coatings, a linear dependence of molecular orientation on the layer thickness appears. In composite coatings containing silver nanoclusters, the effect of selective plasmon absorption was established.
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Dung, Nguyen Thi, Hoang Van Thanh, and Nguyen Dinh Lam. "Influences of Growth Durations on Characteristics of NaYF4:(Yb,Tm) Upconversion Materials." VNU Journal of Science: Natural Sciences and Technology 35, no. 4 (December 23, 2019). http://dx.doi.org/10.25073/2588-1140/vnunst.4965.
Full textAbstract:
NaYF4:(Yb,Tm) upconversion materials were synthesized by the simple hydrothermal method. Growth duration was varied from 4h to 12h under a growth temperature of 150oC. The structural, optical and surface morphology characteristics of the NaYF4:(Yb,Tm) UC materials were investigated. The XRD and SEM results illustrated that the NaYF4:(Yb,Tm) materials were transformed from the multiple phases (hexagonal and cubic) to the single-phase (hexagonal prism) as growth duration being longer than 8h with the average diameter and length of these prisms being about 0.5 µm and 2 µm, respectively. Under 980 nm laser excitation, the NaYF4:(Yb,Tm) emits at peaks of 450 nm (1D2→ 3F4), 475 nm (1G4→3H6), 647 nm (1G4→3F4) and 697 nm (3F3→3H6), with the highest emission belonging to NaYF4:(Yb,Tm) grown for 8h.
Keywords: NaYF4:(Yb,Tm), upconversion materials, photoluminescence, growth duration, hydrothermal method.
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