scholarly journals Modeling of optical properties of hybrid metal-organic nanostructures

Doklady BGUIR ◽  
2022 ◽  
Vol 19 (8) ◽  
pp. 15-19
Author(s):  
A. N. Ponyavina ◽  
K. A. Barbarchyk ◽  
A. D. Zamkovets ◽  
S. A. Tikhomirov
Keyword(s):  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Copper Phthalocyanine ◽  
Efficiency Factor ◽  
Spherical Particles ◽  
Geometrical Parameters ◽  
Organic Nanostructures ◽  
Resonance Band ◽  
Metal Organic

To model spectral characteristics of hybrid metal-organic nanostructures, the extended Mie theory was used, which makes it possible to calculate the extinction efficiency factor (Qext) and the scattering efficiency factor in the near zone (QNF) of two-layer spherical particles placed in an absorbing matrix. Two-layer plasmon nanospheres consisting of a metallic core (Ag, Cu) coated with dielectric shells and located into the copper phthalocyanine (CuPc) matrix were considered. The influence of dielectric shell thickness and refractive index on the characteristics of the surface plasmon resonance of absorption (SPRA) was studied. The possibility of the SPRA band tuning by changing the optical and geometrical parameters of dielectric shells was shown. It was established that dielectric shells allow to shift the surface plasmon resonance band of plasmonic  nanoparticles absorption both  to  short-  and  long-wavelength  spectral  range  depending on the relation between shell and matrix refractive indexes.

scholarly journals Volatile Organic Compound Vapour Measurements Using a Localised Surface Plasmon Resonance Optical Fibre Sensor Decorated with a Metal-Organic Framework

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1420
Author(s):  
Chenyang He ◽  
Liangliang Liu ◽  
Sergiy Korposh ◽  
Ricardo Correia ◽  
Stephen P. Morgan
Keyword(s):  
Surface Plasmon Resonance ◽  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Surface Plasmon ◽  
Optical Fibre ◽  
Plasmon Resonance ◽  
Metal Organic Framework ◽  
Volatile Organic ◽  
Metal Organic ◽  
Organic Framework

A tip-based fibreoptic localised surface plasmon resonance (LSPR) sensor is reported for the sensing of volatile organic compounds (VOCs). The sensor is developed by coating the tip of a multi-mode optical fibre with gold nanoparticles (size: 40 nm) via a chemisorption process and further functionalisation with the HKUST-1 metal–organic framework (MOF) via a layer-by-layer process. Sensors coated with different cycles of MOFs (40, 80 and 120) corresponding to different crystallisation processes are reported. There is no measurable response to all tested volatile organic compounds (acetone, ethanol and methanol) in the sensor with 40 coating cycles. However, sensors with 80 and 120 coating cycles show a significant redshift of resonance wavelength (up to ~9 nm) to all tested volatile organic compounds as a result of an increase in the local refractive index induced by VOC capture into the HKUST-1 thin film. Sensors gradually saturate as VOC concentration increases (up to 3.41%, 4.30% and 6.18% in acetone, ethanol and methanol measurement, respectively) and show a fully reversible response when the concentration decreases. The sensor with the thickest film exhibits slightly higher sensitivity than the sensor with a thinner film. The sensitivity of the 120-cycle-coated MOF sensor is 13.7 nm/% (R2 = 0.951) with a limit of detection (LoD) of 0.005% in the measurement of acetone, 15.5 nm/% (R2 = 0.996) with an LoD of 0.003% in the measurement of ethanol and 6.7 nm/% (R2 = 0.998) with an LoD of 0.011% in the measurement of methanol. The response and recovery times were calculated as 9.35 and 3.85 min for acetone; 5.35 and 2.12 min for ethanol; and 2.39 and 1.44 min for methanol. The humidity and temperature crosstalk of 120-cycle-coated MOF was measured as 0.5 ± 0.2 nm and 0.5 ± 0.1 nm in the humidity range of 50–75% relative humidity (RH) and temperature range of 20–25 °C, respectively.

scholarly journals Investigation of the Influence of the Molecular Weight of Polyethyleneglycols on the Optical Properties and Dispersed Characteristics of Sols of Au Nanoparticles used in Medicine

2021 ◽  
pp. 268-280
Author(s):  
Abdul-Fattah Visirkhazhievich Ibragimov ◽  
Iman Ibragimovna Magomadova ◽  
Maryana Vyacheslavovna Teberdieva ◽  
Seda Alievna Ferzauli ◽  
Tamila Muslimovna Dolaeva ◽  
...  
Keyword(s):  
Optical Properties ◽  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Optical Density ◽  
Plasmon Resonance ◽  
Hydrodynamic Radius ◽  
Au Nanoparticles ◽  
Plasmon Resonance Band ◽  
Resonance Band ◽  
Peg 8000

In this work, the synthesis of Au nanoparticles stabilized with polyethyleneglycols with different molecular weights from 200 to 8000 Da was carried out. The synthesis was carried out by the method of chemical reduction in an aqueous medium using sodium citrate as a reducing agent. The dependence of the optical properties on the concentration and molar mass of polyethyleneglycol was studied in the obtained samples of Au nanoparticles. The absorption spectra were recorded using an SF-56 optical spectrometer. The studies were carried out in the visible range of the spectrum from 400 to 800 nm. It was found that the type of spectrum, the position of the surface plasmon resonance band and the optical density of the samples of Au nanoparticles stabilized with PEG-8000 with a concentration of 10 and 20% did not undergo significant changes during storage, which characterizes the high aggregate stability of these sols. The dispersed characteristics of these samples of sols of Au nanoparticles were also studied. The studies were carried out using photon-correlation spectroscopy by the method of dynamic light scattering. It is established that an increase in the concentration of the stabilizer leads to an increase in the average hydrodynamic radius of the particles. This fact is associated with an increase in the thickness of the stabilizer layer and with the "stitching" of the polymer layer of Au nanoparticles with the formation of aggregates. Thus, the best result was found in PEG-8000 samples with concentrations of 10 and 20%, since the type of spectrum, the position of the surface plasmon resonance band and the optical density did not undergo significant changes. Based on the data obtained, it can be concluded that the best stabilizer for Au nanoparticles obtained by the citrate method is PEG-8000 with a concentration of at least 10 %. It is important to note that with an increase in the concentration of the stabilizer, the average hydrodynamic radius of the particles increases. This fact is associated with an increase in the thickness of the stabilizer layer and with the "stitching" of Au nanoparticles.

scholarly journals Evolution and Tailoring of DUV Plasmonic Properties in Al Nanoparticle Arrays by UV Irradiation

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Yanyue Ding ◽  
Jian Chen ◽  
Gan Xu ◽  
Fei Liu ◽  
Min Han
Keyword(s):  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Ultraviolet Irradiation ◽  
Near Field ◽  
Surface Oxidation ◽  
Blue Shift ◽  
Nanoparticle Arrays ◽  
Plasmon Band ◽  
Resonance Band

Ultraviolet irradiation was used to tailor the surface plasmon band of the densely distributed aluminium nanoparticle arrays fabricated by gas-phase deposition. We showed that the broad surface plasmon resonance band of the as-prepared sample could be tuned to a sharp and strong resonance band in the deep ultraviolet optical range, with a large blue shift of the peak wavelength. The evolution of the surface plasmon resonance properties was attributed to the ultraviolet irradiation-improved surface oxidation of the nanoparticles, which eliminated the near-field couplings between the closely spaced nanoparticles by increasing their interspacing.

A sensitive plasmonic probe based on in situ growth of a Ag shell on a Au@N-CD nanocomposite for detection of isoniazid in environmental and biological samples

2019 ◽  
Vol 43 (15) ◽  
pp. 5980-5986 ◽  
Author(s):  
Tooba Hallaj ◽  
Mohammad Amjadi
Keyword(s):  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Wavelength Shift ◽  
In Situ Growth ◽  
Plasmon Resonance Band ◽  
Resonance Band ◽  
Environmental And Biological Samples

In this study, a new plasmonic probe based on the wavelength shift of the surface plasmon resonance band of a Au@N-CD nanocomposite was introduced for the determination of isoniazid.

Multiwavelength excitation of photosensitizers interacting with gold nanoparticles and its impact on optical properties of their hybrid mixtures

2015 ◽  
Vol 17 (41) ◽  
pp. 27366-27372 ◽  
Author(s):  
Michał Kotkowiak ◽  
Alina Dudkowiak
Keyword(s):  
Gold Nanoparticles ◽  
Optical Properties ◽  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Surface Plasmon Resonance Band ◽  
Plasmon Resonance Band ◽  
Resonance Band ◽  
Hybrid Mixtures

Different behavior of the mixtures on excitation with the wavelengths from the Soret and Q bands of the dyes and with those corresponding to the surface plasmon resonance band of gold nanoparticles, was analyzed.

Optical Properties of Shaped Silver Nanoparticles

2008 ◽  
Vol 8 (7) ◽  
pp. 3511-3515 ◽  
Author(s):  
Vesna V. Vodnik ◽  
Dušan K. Božanić ◽  
Nataša Bibić ◽  
Zoran V. Šaponjić ◽  
Jovan M. Nedeljković
Keyword(s):  
Silver Nanoparticles ◽  
Optical Properties ◽  
Absorption Spectrum ◽  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Nanocomposite Film ◽  
Reducing Agent ◽  
Plasmon Resonance Band ◽  
Resonance Band

The influence of shape and dielectric property of surrounding media on surface plasmon absorption band of silver nanoparticles was studied. Spherical silver nanoparticles (d = 5.6 nm) synthesized in water using NaBH4 as a reducing agent are transferred in non-polar solvent (chloroform) with phase-transfer reagent oleylamine. The absorption spectrum of oleylamine-capped silver nanoparticles dispersed in chloroform shows a strong surface plasmon resonance band that is 19 nm red-shifted compared to unmodified particles in water. The values for peak position and corresponding half widths are compared with theoretical calculations based on Mie theory. Prismatic and plate-like silver nanoparticles were synthesized in water using trisodium citrate as a reducing agent and cetyltrimethylammonium bromide as stabilizer. Due to structural anisotropy of prismatic and plate-like silver nanoparticles three surface plasmon resonance bands were observed in absorption spectrum. Nanocomposites consisting of non-spherical silver nanoparticles and polyvinyl alcohol exhibit different optical properties compared to water colloid. Instead of three surface plasmon bands, nanocomposite film has only one peak at 460 nm. Reason for appearance of single surface plasmon resonance band in nanocomposite film was discussed according to Maxwell-Garnet theory.

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