Environmental assessment of 2-mercaptobenzimidazole based on the surface plasmon resonance band of gold nanoparticles

2013 ◽  
Vol 185 (11) ◽  
pp. 9037-9042 ◽  
Author(s):  
Saadat Rastegarzadeh ◽  
Zeinab Barkat Rezaei
2015 ◽  
Vol 17 (41) ◽  
pp. 27366-27372 ◽  
Author(s):  
Michał Kotkowiak ◽  
Alina Dudkowiak

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.


2008 ◽  
Vol 3 ◽  
pp. 115-122
Author(s):  
Víctor Rentería-Tapia ◽  
Jorge A. García-Macedo ◽  
Guadalupe Valverde-Aguilar

Sol-gel silica films containing gold ions were prepared with and without citric acid (capping agent). Heat treatment of these films in hydrogen atmosphere (reducing agent) leads to the formation of gold nanoparticles. The experimental optical spectra of the gold nanoparticles prepared with citric acid revealed a surface plasmon resonance band located at 585 nm. Transmission electronic microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM) measurements revealed the formation of prolate gold nanoparticles (6.4 nm of average diameter) and aggregates dispersed in silica matrix. On the other hand, gold nanoparticles in sol-gel silica films prepared without citric acid exhibited a splitting in surface plasmon resonance band for the prolate gold nanoparticles with an average size <12 nm. On further annealing the samples in oxygen atmosphere, the gold nanoparticles prepared with citric acid exhibited high stability in contrast to the samples prepared without citric acid. This stability probably depends on the formation of a microporous structure of silica produced by the citric acid. The optical properties of the metallic nanoparticles were modeled using Gans theory.


Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1559
Author(s):  
Yanchao Lyu ◽  
Álvaro Martínez ◽  
Federica D’Incà ◽  
Fabrizio Mancin ◽  
Paolo Scrimin

The biotin–avidin interaction is used as a binding tool for the conjugation of biomolecules for more diverse applications; these include nanoparticle conjugation. Despite this, a thorough investigation on the different aggregates that may result from the interaction of biotinylated nanoparticles (gold nanoparticles, AuNPs, in this work) with avidin has not been carried out so far. In this paper, we address this problem and show the type of aggregates formed under thermodynamic and kinetic control by varying the biotinylated AuNP/avidin ratio and the order of addition of the two partners. The analysis was performed by also addressing the amount of protein able to interact with the AuNPs surface and is fully supported by the TEM images collected for the different samples and the shift of the surface plasmon resonance band. We show that the percentage of saturation depends on the size of the nanoparticles, and larger nanoparticles (19 nm in diameter) manage to accommodate a relatively larger amount of avidins than smaller ones (11 nm). The AuNPs are isolated or form small clusters (mostly dimers or trimers) when a large excess or a very low amount of avidin is present, respectively, or form large clusters at stoichiometric concentration of the protein. Daisy-like systems are formed under kinetic control conditions when nanoparticles first covered with the protein are treated with a second batch of biotinylated ones but devoid of avidin.


2020 ◽  
Vol 2 (1) ◽  
pp. 5-18
Author(s):  
Magda Mohamed Ayad Ayad ◽  
Hisham Ezzat Abdellatef ◽  
Mervat Mohamed Hosny ◽  
Naglaa Abdel-Sattar Kabil

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