Ultra-fast electron capture by electrosterically-stabilized gold nanoparticles

Nanoscale ◽  
2015 ◽  
Vol 7 (27) ◽  
pp. 11545-11551 ◽  
Author(s):  
Khashayar Ghandi ◽  
Alexander D. Findlater ◽  
Zahid Mahimwalla ◽  
Connor S. MacNeil ◽  
Ernest Awoonor-Williams ◽  
...  

Faster than electron solvation transfer to gold nanoparticles in water when stabilized by non-covalent bonds with strong intermolecular interactions.

2001 ◽  
Vol 704 ◽  
Author(s):  
Sheng-Ming Shih ◽  
Wei-Fang Su ◽  
Yuh-Jiuan Lin ◽  
Cen-Shawn Wu ◽  
Chii-Dong Chen

AbstractNovel arrays of gold nanoparticles with sulfur containing fullerene nanoparticles were self-assembled through the formation of Au-S covalent bonds. Disulfide functional groups were introduced into C60 molecule by reacting propyl 2-aminoethyl disulfide with C60. The two dimensional(2D) arrays were formed at the interface of aqueous phase of gold particles and organic phase of fullerene particles as a blue transparent film. TEM images showed that the fullerene spacing between adjacent Au(~10 nm) particles was about 2.1±0.4 nm, which was consistent with the result of 2.18 nm by molecular molding calculations(MM+). The arrays were deposited on the top of pairs of gold electrodes to form 2D colloidal single electron devices. The electrode pairs were made by electron beam lithography techniques, and the separation between tips of the two electrodes in a pair was less then 100 nm. Transport measurements at low temperatures exhibited Coulomb-Blockade type current-voltage characteristics, the lower the temperature the more pronounced the Coulomb gap. Also, step-by-step method was used to assemble one-dimensional(1D) array of gold nanoparticles with fullerene derivative between two electrodes spaced with 15 nm. The Coulomb blockade behavior of 1D arrays was clearer than that of 2D arrays.


2020 ◽  
Author(s):  
Xiaoning Zhang ◽  
Meifeng Li ◽  
Yuanping Lv ◽  
Xiaoling Sun ◽  
Yao Han ◽  
...  

Abstract Gold nanoparticles (AuNPs) are modified immediately by the adsorption of β-lactoglobulin (βlg) when designed as colorimetric probe in raw milk, leading to the formation of a protein corona. This adsorption results mainly from a fast electrostatic force and a slow formation of Au-S covalent bonds, which is a precondition for the use of AuNPs in biodetection. The proteins corona influences the structure and bioactivity of adsorbed protein, such as the allergy. In this study, the mechanism of βlg adsorbed on AuNPs was investigated in terms of stoichiometry, binding affinity (Ka), time evolution of Au-S bond, and general secondary structure changes to address the desensitization of AuNPs. The results show that about 3,600 βlg are adsorbed on a single AuNPs, and the Ka is 2.9 ± 0.7 × 10 6 M -1 . The formation of Au-S bonds takes about 9 h, which is the time needed for complete changes in secondary structure and the IgE combining capacity. The structure of allergenic epitopes assigned to β-sheet was destroyed by the formation of Au-S bond, then induced to the decrease allergy. Furthermore, Fourier transform infrared spectroscopy confirmed a decrease in β-sheet contents after conjugated with AuNPs.


2018 ◽  
Vol 6 (6) ◽  
pp. 1413-1420 ◽  
Author(s):  
Alexandra I. Zvyagina ◽  
Alexander A. Ezhov ◽  
Ivan N. Meshkov ◽  
Vladimir K. Ivanov ◽  
Kirill P. Birin ◽  
...  

Intermolecular interactions in thin films of organic dyes control the enhancement of the optical absorption by collective plasmons of gold nanoparticles.


2008 ◽  
Vol 8 (8) ◽  
pp. 3828-3837 ◽  
Author(s):  
Víctor Meza-Laguna ◽  
Elena V. Basiuk ◽  
Edgar Alvarez-Zauco ◽  
Taras Yu. Gromovoy ◽  
Oscar Amelines-Sarria ◽  
...  

We report on the preparation of fullerene C60 thin films chemically cross-linked with octane-1,8-dithiol, which are capable of binding gold nanoparticles. The formation of a polymer was directly proved by means of laser desorption/ionization time-of-flight mass spectra, in which we observed the cleavage of fullerene–dithiol polymer at different bonds. Fourier-transform infrared, Raman and UV-visible spectra of the functionalized films exhibited notorious changes due to the formation of new covalent bonds between C60 molecules and bifunctional thiol. We further demonstrated that the dithiol-functionalized fullerene can be employed as a support for stable and homogeneous deposition of gold nanoparticles. Their average size is about 5 nm according to high-resolution transmission electron microscopy observations, and up to 20 nm, as found from scanning tunneling microscopy images. The proposed binding mechanism is through a strong coordination attachment between Au nanoclusters and sulfur donor atoms of the functionalized fullerene, as supported by density functional theory calculations.


2001 ◽  
Vol 704 ◽  
Author(s):  
Sheng-Ming Shih ◽  
Wei-Fang Su ◽  
Yuh-Jiuan Lin ◽  
Cen-Shawn Wu ◽  
Chii-Dong Chen

AbstractNovel arrays of gold nanoparticles with sulfur containing fullerene nanoparticles were self-assembled through the formation of Au-S covalent bonds. Disulfide functional groups were introduced into C60 molecule by reacting propyl 2-aminoethyl disulfide with C60. The two dimensional(2D) arrays were formed at the interface of aqueous phase of gold particles and organic phase of fullerene particles as a blue transparent film. TEM images showed that the fullerene spacing between adjacent Au(~10 nm) particles was about 2.1±0.4 nm, which was consistent with the result of 2.18 nm by molecular molding calculations(MM+). The arrays were deposited on the top of pairs of gold electrodes to form 2D colloidal single electron devices. The electrode pairs were made by electron beam lithography techniques, and the separation between tips of the two electrodes in a pair was less then 100 nm. Transport measurements at low temperatures exhibited Coulomb-Blockade type current-voltage characteristics, the lower the temperature the more pronounced the Coulomb gap. Also, step-by-step method was used to assemble one-dimensional(1D) array of gold nanoparticles with fullerene derivative between two electrodes spaced with 15 nm. The Coulomb blockade behavior of 1D arrays was clearer than that of 2D arrays.


2001 ◽  
Vol 707 ◽  
Author(s):  
Sheng-Ming Shih ◽  
Wei-Fang Su ◽  
Yuh-Jiuan Lin ◽  
Cen-Shawn Wu ◽  
Chii-Dong Chen

ABSTRACTNovel arrays of gold nanoparticles with sulfur containing fullerene nanoparticles were self-assembled through the formation of Au-S covalent bonds. Disulfide functional groups were introduced into C60 molecule by reacting propyl 2-aminoethyl disulfide with C60. The two dimensional(2D) arrays were formed at the interface of aqueous phase of gold particles and organic phase of fullerene particles as a blue transparent film. TEM images showed that the fullerene spacing between adjacent Au(∼10 nm) particles was about 2.1±0.4 nm, which was consistent with the result of 2.18 nm by molecular molding calculations(MM+). The arrays were deposited on the top of pairs of gold electrodes to form 2D colloidal single electron devices. The electrode pairs were made by electron beam lithography techniques, and the separation between tips of the two electrodes in a pair was less then 100 nm. Transport measurements at low temperatures exhibited Coulomb-Blockade type current-voltage characteristics, the lower the temperature the more pronounced the Coulomb gap. Also, step-by-step method was used to assemble one-dimensional(1D) array of gold nanoparticles with fullerene derivative between two electrodes spaced with 15 nm. The Coulomb blockade behavior of 1D arrays was clearer than that of 2D arrays.


Nanomaterials ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1506 ◽  
Author(s):  
Ana Isabel Ruiz-Carmuega ◽  
Celia Garcia-Hernandez ◽  
Javier Ortiz ◽  
Cristina Garcia-Cabezon ◽  
Fernando Martin-Pedrosa ◽  
...  

Voltametric sensors formed by the combination of a sulfur-substituted zinc phthalocyanine (ZnPcRS) and gold nanoparticles capped with tetraoctylammonium bromide (AuNPtOcBr) have been developed. The influence of the nature of the interaction between both components in the response towards catechol has been evaluated. Electrodes modified with a mixture of nanoparticles and phthalocyanine (AuNPtOcBr/ZnPcRS) show an increase in the intensity of the peak associated with the reduction of catechol. Electrodes modified with a covalent adduct-both component are linked through a thioether bond-(AuNPtOcBr-S-ZnPcR), show an increase in the intensity of the oxidation peak. Voltammograms registered at increasing scan rates show that charge transfer coefficients are different in both types of electrodes confirming that the kinetics of the electrochemical reaction is influenced by the nature of the interaction between both electrocatalytic materials. The limits of detection attained are 0.9 × 10−6 mol∙L−1 for the electrode modified with the mixture AuNPtOcBr/ZnPcRS and 1.3 × 10−7 mol∙L−1 for the electrode modified with the covalent adduct AuNPtOcBr-S-ZnPcR. These results indicate that the establishment of covalent bonds between nanoparticles and phthalocyanines can be a good strategy to obtain sensors with enhanced performance, improving the charge transfer rate and the detection limits of voltammetric sensors.


2007 ◽  
Vol 36 (5) ◽  
pp. 686-687
Author(s):  
Youli Qi ◽  
Miao Chen ◽  
Shan Liang ◽  
Jing Zhao ◽  
Wu Yang ◽  
...  

2021 ◽  
Vol 31 (3) ◽  
pp. 167-173
Author(s):  
Zehraa Najim Abdul-Ameer

The amazing wide range, applications of gold nanoparticles corresponding to excellent optical and electronic properties enhance utilization of Au NP as PH sensor. Gold nanoparticles were synthesized in simple and rapid Turkevich method to accomplish optical sensing technologies covalent or non-covalent, bonds formation causes, aggregation of the nanoparticles in the target substance. Au nanoparticles characterization was studied using XRD, UV-spectroscopy and SEM. XRD indicate polycrystalline. Nanoparticles with two different sizes according to reducing agent amount to obtain 20 30 nm. Optical energy gap was calculated for both particle size to find it (2.13) eV for 30nm particle size and (2.33) eV for 20nm.Scanning Electron Microscope showed spherical shape particles. PH test were performed to investigate efficiency of Au Np’s for PH sensor and that is found to be excellent results for both sizes with more efficiency for 30 nm due to its rough surface. Which is a fantastic tool and measurement device to test the pH of soil, food, and other puncture-worthy applications.


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