Facile Preparation of Gold Nanoparticles via Simultaneous Electrodissolution/Chemical Reduction Processes for the Electrochemical Oxidation and Sensing of Ascorbic Acid

2017 ◽  
Vol 164 (14) ◽  
pp. H1041-H1046 ◽  
Author(s):  
Peng Li ◽  
Hui Zhang ◽  
Dongsheng Lai ◽  
Shili Xu ◽  
Yue Xia ◽  
...  
2020 ◽  
Vol 16 (7) ◽  
pp. 905-913
Author(s):  
Youyuan Peng ◽  
Qingshan Miao

Background: L-Ascorbic acid (AA) is a kind of water soluble vitamin, which is mainly present in fruits, vegetables and biological fluids. As a low cost antioxidant and effective scavenger of free radicals, AA may help to prevent diseases such as cancer and Parkinson’s disease. Owing to its role in the biological metabolism, AA has also been utilized for the therapy of mental illness, common cold and for improving the immunity. Therefore, it is very necessary and urgent to develop a simple, rapid and selective strategy for the detection of AA in various samples. Methods: The molecularly imprinted poly(o-phenylenediamine) (PoPD) film was prepared for the analysis of L-ascorbic acid (AA) on gold nanoparticles (AuNPs) - multiwalled carbon nanotubes (MWCNTs) modified glass carbon electrode (GCE) by electropolymerization of o-phenylenediamine (oPD) and AA. Experimental parameters including pH value of running buffer and scan rates were optimized. Scanning electron microscope (SEM), fourier-transform infrared (FTIR) spectra, cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were utilized for the characterization of the imprinted polymer film. Results: Under the selected experimental conditions, the DPV peak currents of AA exhibit two distinct linear responses ranging from 0.01 to 2 μmol L-1 and 2 to 100 μmol L-1 towards the concentrations of AA, and the detection limit was 2 nmol L-1 (S/N=3). Conclusion: The proposed electrochemical sensor possesses excellent selectivity for AA, along with good reproducibility and stability. The results obtained from the analysis of AA in real samples demonstrated the applicability of the proposed sensor to practical analysis.


2010 ◽  
Vol 43 (18) ◽  
pp. 2809-2822 ◽  
Author(s):  
T. G. Satheesh Babu ◽  
P. V. Suneesh ◽  
T. Ramachandran ◽  
Bipin Nair

2021 ◽  
Author(s):  
Yi-wei Sun ◽  
Hui Liang ◽  
Kun-qi Zong ◽  
Xin Che ◽  
Da-li Meng

Using NIR irradiation, gold nanomaterials loaded with natural products can achieve targeted release as well as better anti-tumor activity.


2020 ◽  
Author(s):  
Mehvesh Hameed ◽  
Seema Panicker ◽  
Sallam Hasan Abdallah ◽  
Amir A. Khan ◽  
Changseok Han ◽  
...  

We synthesized protein-coated gold nanoparticles using green and chemical reduction routes for cellular uptake study. In the current work, we coated gold-aryl nanoparticles of the type AuNPs-C<sub>6</sub>H<sub>4</sub>-4-COOH with BSA, collagen, zein and lysozyme proteins. Both routes were carried out without phase-transfer catalysts or extraneous stabilizing agents. High crystallinity of the AuNPs synthesized by the green route can be seen in the transmission electron microscopy images. <a>Osteosarcoma cancer cells are malignant bone tumors with abnormal cellular functions. Studies using MG-63 cells will provide mechanistic suggestions on the details of the amplification in tumors. </a>We studied the cellular uptake of the bioconjugates by MG-63 osteosarcoma cells using laser confocal fluorescence microscopy (LCFM) and flow cytometry. In the LCFM study, BSA-AuNPs was uptaken most efficiently of all protein-coated gold nanoparticles synthesized by the green route. Zein and lysozyme coated nanoparticles, though small sizes, prepared by the green method were not efficiently uptaken by MG-63. The two nanoparticles are negatively charged and zein is also a hydrophobic coat. The difference in hydrophobicity and charge might have affected the internalization. All of those coated nanoparticles that were efficiently uptaken can potentially be used as diagnostic and therapeutic agents for osteosarcoma.


1973 ◽  
Vol 7 (11) ◽  
pp. 708-710 ◽  
Author(s):  
M. �. Meller ◽  
L. G. Seleznev ◽  
F. I. Lukhnitskii ◽  
L. M. Sukhmaneva ◽  
M. A. Veksler ◽  
...  

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