Chitosan Capped Colloidal Gold Nanoparticles for Sensing Zinc Ions in Water

2012 ◽  
Vol 16 ◽  
pp. 55-61 ◽  
Author(s):  
Sujira Promnimit ◽  
T. Bera ◽  
S. Baruah ◽  
Joydeep Dutta
Keyword(s):  
Gold Nanoparticles ◽  
Colloidal Gold ◽  
Metal Ion ◽  
Aqueous Media ◽  
Molar Ratio ◽  
Zinc Ions ◽  
Colloidal Gold Nanoparticles ◽  
Plasmon Peak ◽  
The Stability ◽  
Static Stabilizer

In this work, we report sensing of Zn2+ ions using chitosan capped colloidal gold nanoparticles in aqueous media. The chitosan capping not just acted as an electro-static stabilizer to the colloidal gold nanoparticles, but also could bind to Zn2+ ions if present in the solution. However, the Zn2+ ions chelation to the chitosan capping decreased the stability of the colloidal gold hence shifted the surface plasmon peak to higher wavelengths. The extent of this red shift was found to be dependent on the concentration of the Zn2+ ions and therefore the presence of Zn2+ ions could be determined both qualitatively and quantitatively by analyzing the optical spectra of the chitosan capped gold nanoparticles. The sensing capability was also affected by the size of the nanoparticles, which could be tuned by adjusting the molar ratio of the reducing agent and the gold salt to the desired levels. Optical characteristics showed satisfactory results in estimating the amount of Zn2+ ions in water. This is thus a promising method for on the spot assessment of heavy metal ion concentrations in water.

scholarly journals Synthesis and Optical Properties of Colloidal Gold Nanoparticles for Biomedical Applications

2011 ◽  
Vol 21 (1) ◽  
pp. 63 ◽  
Author(s):  
Nghiem Thi Ha Lien ◽  
Vu Xuan Hoa ◽  
Vu Thi Thuy Duong ◽  
Nguyen Van Tinh ◽  
Tran Hong Nhung
Keyword(s):  
Gold Nanoparticles ◽  
Colloidal Gold ◽  
Biomedical Applications ◽  
Strong Dependence ◽  
Trisodium Citrate ◽  
Visible Range ◽  
Chloroauric Acid ◽  
Stabilizing Agents ◽  
Colloidal Gold Nanoparticles ◽  
The Stability

The gold nanoparticle solutions are well known as an extremely sensitive biomedical analytical tool due to the strong dependence of their absorption in the visible range on the environment. In this work, the colloidal nano golds were synthesized from metal precursor chloroauric acid (HAuCl4) using trisodium citrate dehydrate (C6H5O7Na3) as reducing and stabilizing agents. The optical characterization - absorption of colloidal gold solution have been investigated under the different synthetic conditions such as: reducing agent concentration, concentration of auric ion, pH, duration of reaction and aging time. The results show that the absorption and the stability of the colloidal gold nanoparticles depend robustly on the synthetic conditions and pH of environment.

Dense aqueous colloidal gold nanoparticles prepared from highly concentrated precursor solution

2011 ◽  
Vol 362 (2) ◽  
pp. 325-329 ◽  
Author(s):  
Tetsuro Soejima ◽  
Seisaku Oshiro ◽  
Yasuji Nakatsuji ◽  
Seishiro Ito
Keyword(s):  
Gold Nanoparticles ◽  
Colloidal Gold ◽  
Precursor Solution ◽  
Colloidal Gold Nanoparticles

An enhanced ELISA based on modified colloidal gold nanoparticles for the detection of Pb(II)

2011 ◽  
Vol 26 (8) ◽  
pp. 3700-3704 ◽  
Author(s):  
Yu Zhou ◽  
Xiang-Li Tian ◽  
Yan-Song Li ◽  
Feng-Guang Pan ◽  
Yuan-Yuan Zhang ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Colloidal Gold ◽  
Colloidal Gold Nanoparticles

Effect of Voltage on Colloidal Gold (Au) Nanoparticles Produced Using Electro-Dissolution-Reduction Method

2015 ◽  
Vol 1115 ◽  
pp. 386-389
Author(s):  
Haroon Haiza ◽  
I.I. Yaacob ◽  
Ahmad Zahirani Ahmad Azhar
Keyword(s):  
Gold Nanoparticles ◽  
Electron Microscope ◽  
Colloidal Gold ◽  
Reduction Process ◽  
Chloride Ions ◽  
Complex Ions ◽  
Dc Power ◽  
Colloidal Gold Nanoparticles ◽  
Transmission Electron ◽  
The Mean

Colloidal gold nanoparticles have been successfully prepared using a simple two-electrode cells connected to a DC power supply. During the electro-dissolution-reduction process, the bulk gold at the anode oxidized into gold cations which then reacted with the chloride ions to form aurochloride complex. The complex ions were then reduced by the citrate ion to form colloidal gold nanoparticles. The size and shape of the nanoparticles were modulated by varying the terminal voltages. The colloidal gold nanoparticles obtained were characterized by field-emission scanning electron microscope (FESEM), transmission electron microscope (TEM) and ultraviolet-visible spectrophotometer (UV-Vis). From FESEM analysis, it was found that by increasing the voltage, the size of colloidal gold nanoparticles produced marginally decreased. The mean sizes of gold nanoparticles were roughly about 23.5 nm, 23.2 nm and 19.3 nm for 32 V, 36 V and 40 V, respectively. TEM micrograph showed that the shape of gold nanoparticles obtained is almost spherical. The characteristic peaks of UV-Vis spectra revealed that the suspension was indeed colloidal gold nanoparticles. Keywords: Gold, Nanoparticles, Electro-dissolution-reduction

scholarly journals Back Cover: Unconventional Chain-Growth Mode in the Assembly of Colloidal Gold Nanoparticles (Angew. Chem. Int. Ed. 32/2012)

2012 ◽  
Vol 51 (32) ◽  
pp. 8122-8122 ◽  
Author(s):  
Hong Wang ◽  
Liyong Chen ◽  
Xiaoshuang Shen ◽  
Liangfang Zhu ◽  
Jiating He ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Colloidal Gold ◽  
Growth Mode ◽  
Chain Growth ◽  
Back Cover ◽  
Colloidal Gold Nanoparticles

scholarly journals Detection and difference analysis of the enzyme activity of colloidal gold nanoparticles with negatively charged surfaces prepared by different reducing agents

2021 ◽  
Author(s):  
Junjun Cao ◽  
Jie Zhang ◽  
Ning Yuan ◽  
Yixiao Sun ◽  
Zhihua Xu ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Enzyme Activity ◽  
Hydroxyl Radical ◽  
Colloidal Gold ◽  
Negative Charge ◽  
Linear Chain ◽  
Reducing Agents ◽  
Difference Analysis ◽  
Charged Surfaces ◽  
Colloidal Gold Nanoparticles

Abstract Research on the activity of nanoenzymes has always been a focus of nanomaterials. In this study, several reducing agents with different structures were used to prepare colloidal gold with a negative charge and similar size by controlling the temperature and pH. The affinity analysis of the substrate H 2 O 2 and TMB showed that the activity of colloidal gold nanoenzymes prepared by different reducing agents was in the order of Cc, Hq, Rs, Vc, Ga, Sc, Sm, St. The rule is that the enzyme activity of colloidal gold reduced by benzene ring is higher than that of colloidal gold enzyme reduced by linear chain. Finally, we discussed the activity of colloidal gold peroxidase from the number and position of isomers and functional groups, and demonstrated that the nanoenzyme activity affected the surface activity of colloidal gold, the elimination of hydroxyl radical and TMB binding efficiency.

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