Optical spectra of conjugated gold nano-colloids; Scattering cross section and effects of solvent and polydispersity

In this paper, a numerical study has been carried out on the effects of the type of solvent and polydispersity of gold nanoparticles (Au NPs) on the absorption and dispersion spectra of its colloidal solution. A theoretical model has been used in which, in addition to considering surface agents, the...

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Main Authors: Ehsan Koushki, Hamid Akherat Doost
Format: Article
Language:English
Published: Elsevier 2025-01-01
Series:Results in Chemistry
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Online Access:http://www.sciencedirect.com/science/article/pii/S2211715625000074
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author Ehsan Koushki
Hamid Akherat Doost
author_facet Ehsan Koushki
Hamid Akherat Doost
author_sort Ehsan Koushki
collection DOAJ
description In this paper, a numerical study has been carried out on the effects of the type of solvent and polydispersity of gold nanoparticles (Au NPs) on the absorption and dispersion spectra of its colloidal solution. A theoretical model has been used in which, in addition to considering surface agents, the effect of solvent and polydispersity of the particles can be applied. Different cases were simulated in which the effect of ethylene and methanol alcohol added to the aqueous solution of Au NPs was studied. The refractive index of the mixed solvent was investigated at different percentages of alcohol and at different temperatures. The effect of these factors on the absorption peak which is a result of localized surface plasmon resonance (LSPR) was investigated and it was observed that increasing the refractive index of the solvent (by adding alcohol) can lead to red-shift of the plasmonic peak and the overall increase in the refractive index. Also, effects of polydispersity on the absorption and dispersion curves were studied. To study the optical scattering of Au nano-colloid, the angular dispersion distribution profiles for different hydrodynamic diameters were calculated using the Discrete Dipole Approximation (DDA) model that clearly showed the effect of the hydrodynamic diameter of the target particles on the scattering patterns. The results of this investigation are very important in the interpretation of the absorption spectra of Au NPs, especially the wavelength and width of the plasmonic peak, and through the study of these spectral characteristics, useful information can be obtained about the surface agents and the solvent, which can open a new aperture to sensor applications of Au NPs, such as optical sensors, biomedical imaging and optical communication technologies. These results can be of interest to experimental researchers working in the field of Au NPs and help to interpret spectral data.
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spelling doaj-art-a2c06ebe56224d288b5bc69f3d497a222025-01-29T05:00:59ZengElsevierResults in Chemistry2211-71562025-01-0113102024Optical spectra of conjugated gold nano-colloids; Scattering cross section and effects of solvent and polydispersityEhsan Koushki0Hamid Akherat Doost1Department of Physics, Faculty of Basic Science, Hakim Sabzevari University, Sabzevar 96179-76487, Iran; Corresponding author.Department of Physics, Central Tehran Branch, Islamic Azad University, Tehran 14676-6831, IranIn this paper, a numerical study has been carried out on the effects of the type of solvent and polydispersity of gold nanoparticles (Au NPs) on the absorption and dispersion spectra of its colloidal solution. A theoretical model has been used in which, in addition to considering surface agents, the effect of solvent and polydispersity of the particles can be applied. Different cases were simulated in which the effect of ethylene and methanol alcohol added to the aqueous solution of Au NPs was studied. The refractive index of the mixed solvent was investigated at different percentages of alcohol and at different temperatures. The effect of these factors on the absorption peak which is a result of localized surface plasmon resonance (LSPR) was investigated and it was observed that increasing the refractive index of the solvent (by adding alcohol) can lead to red-shift of the plasmonic peak and the overall increase in the refractive index. Also, effects of polydispersity on the absorption and dispersion curves were studied. To study the optical scattering of Au nano-colloid, the angular dispersion distribution profiles for different hydrodynamic diameters were calculated using the Discrete Dipole Approximation (DDA) model that clearly showed the effect of the hydrodynamic diameter of the target particles on the scattering patterns. The results of this investigation are very important in the interpretation of the absorption spectra of Au NPs, especially the wavelength and width of the plasmonic peak, and through the study of these spectral characteristics, useful information can be obtained about the surface agents and the solvent, which can open a new aperture to sensor applications of Au NPs, such as optical sensors, biomedical imaging and optical communication technologies. These results can be of interest to experimental researchers working in the field of Au NPs and help to interpret spectral data.http://www.sciencedirect.com/science/article/pii/S2211715625000074Gold nanoparticlesDispersion curveLocalized surface plasmon resonancePolydispersityAlcohol-water mixture
spellingShingle Ehsan Koushki
Hamid Akherat Doost
Optical spectra of conjugated gold nano-colloids; Scattering cross section and effects of solvent and polydispersity
Results in Chemistry
Gold nanoparticles
Dispersion curve
Localized surface plasmon resonance
Polydispersity
Alcohol-water mixture
title Optical spectra of conjugated gold nano-colloids; Scattering cross section and effects of solvent and polydispersity
title_full Optical spectra of conjugated gold nano-colloids; Scattering cross section and effects of solvent and polydispersity
title_fullStr Optical spectra of conjugated gold nano-colloids; Scattering cross section and effects of solvent and polydispersity
title_full_unstemmed Optical spectra of conjugated gold nano-colloids; Scattering cross section and effects of solvent and polydispersity
title_short Optical spectra of conjugated gold nano-colloids; Scattering cross section and effects of solvent and polydispersity
title_sort optical spectra of conjugated gold nano colloids scattering cross section and effects of solvent and polydispersity
topic Gold nanoparticles
Dispersion curve
Localized surface plasmon resonance
Polydispersity
Alcohol-water mixture
url http://www.sciencedirect.com/science/article/pii/S2211715625000074
work_keys_str_mv AT ehsankoushki opticalspectraofconjugatedgoldnanocolloidsscatteringcrosssectionandeffectsofsolventandpolydispersity
AT hamidakheratdoost opticalspectraofconjugatedgoldnanocolloidsscatteringcrosssectionandeffectsofsolventandpolydispersity