Molecularly imprinted polyaniline-ferrocene-sulfonic acid-Carbon dots modified pencil graphite electrodes for chiral selective sensing of D-Ascorbic acid and L-Ascorbic acid: A clinical biomarker for preeclampsia

2015 ◽  
Vol 182 ◽  
pp. 917-928 ◽  
Author(s):  
Indu Pandey ◽  
Shashank Shekhar Jha
Keyword(s):  
Ascorbic Acid ◽  
Carbon Dots ◽  
Sulfonic Acid ◽  
Graphite Electrodes ◽  
Molecularly Imprinted ◽  
Clinical Biomarker

Molecularly Imprinted Sensor for Ascorbic Acid Based on Gold Nanoparticles and Multiwalled Carbon Nanotubes

2020 ◽  
Vol 16 (7) ◽  
pp. 905-913
Author(s):  
Youyuan Peng ◽  
Qingshan Miao
Keyword(s):  
Carbon Nanotubes ◽  
Gold Nanoparticles ◽  
Ascorbic Acid ◽  
Multiwalled Carbon Nanotubes ◽  
Ph Value ◽  
Biological Fluids ◽  
Water Soluble ◽  
Multiwalled Carbon ◽  
Experimental Conditions ◽  
Molecularly Imprinted

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.

scholarly journals Synthesis of Fluorescent Carbon Dots and Their Application in Ascorbic Acid Detection

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1246
Author(s):  
Tengfei Wang ◽  
Hui Luo ◽  
Xu Jing ◽  
Jiali Yang ◽  
Meijun Huo ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Fluorescence Intensity ◽  
Carbon Dots ◽  
Ph Dependence ◽  
Scale Up ◽  
Water Soluble ◽  
Jujube Fruit ◽  
Fluorescent Carbon Dots ◽  
Fluorescent Carbon

Water-soluble fluorescent carbon dots (CDs) were synthesized by a hydrothermal method using citric acid as the carbon source and ethylenediamine as the nitrogen source. The repeated and scale-up synthetic experiments were carried out to explore the feasibility of macroscopic preparation of CDs. The CDs/Fe3+ composite was prepared by the interaction of the CDs solution and Fe3+ solution. The optical properties, pH dependence and stability behavior of CDs or the CDs/Fe3+ composite were studied by ultraviolet spectroscopy and fluorescence spectroscopy. Following the principles of fluorescence quenching after the addition of Fe3+ and then the fluorescence recovery after the addition of asorbic acid, the fluorescence intensity of the carbon dots was measured at λex = 360 nm, λem = 460 nm. The content of ascorbic acid was calculated by quantitative analysis of the changing fluorescence intensity. The CDs/Fe3+ composite was applied to the determination of different active molecules, and it was found that the composite had specific recognition of ascorbic acid and showed an excellent linear relationship in 5.0–350.0 μmol·L−1. Moreover, the detection limit was 3.11 μmol·L−1. Satisfactory results were achieved when the method was applied to the ascorbic acid determination in jujube fruit. The fluorescent carbon dots composites prepared in this study may have broad application prospects in a rapid, sensitive and trace determination of ascorbic acid content during food processing.

scholarly journals Relevance and Standardization of In Vitro Antioxidant Assays: ABTS, DPPH, and Folin–Ciocalteu

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Helena Abramovič ◽  
Blaž Grobin ◽  
Nataša Poklar Ulrih ◽  
Blaž Cigić
Keyword(s):  
Ascorbic Acid ◽  
Chlorogenic Acid ◽  
Gallic Acid ◽  
Caffeic Acid ◽  
Sulfonic Acid ◽  
Epigallocatechin Gallate ◽  
The Other ◽  
Oh Groups ◽  
Standard Compound

Trolox, gallic acid, chlorogenic acid, caffeic acid, catechin, epigallocatechin gallate, and ascorbic acid are antioxidants used as standards for reaction with chromogenic radicals, 2,2-diphenyl-1-picrylhydrazyl (DPPH⋅) and 2,2′-azino-bis-3-ethylbenzotiazolin-6-sulfonic acid (ABTS⋅+), and Folin–Ciocalteu (FC) reagent. The number of exchanged electrons has been analyzed as function of method and solvent. A majority of compounds exchange more electrons in FC assay than in ABTS and DPPH assays. In reaction with chromogenic radicals, the largest number of electrons was exchanged in buffer (pH 7.4) and the lowest reactivity was in methanol (DPPH) and water (ABTS). At physiological pH, the number of exchanged electrons of polyphenols exceeded the number of OH groups, pointing to the important contribution of partially oxidized antioxidants, formed in the course of reaction, to the antioxidant potential. For Trolox, small impact on the number of exchanged electrons was observed, confirming that it is more suitable as a standard compound than the other antioxidants.

A rapid and sensitive turn-on fluorescent probe for ascorbic acid detection based on carbon dots–MnO2 nanocomposites

2017 ◽  
Vol 9 (38) ◽  
pp. 5653-5658 ◽  
Author(s):  
Yalei Hu ◽  
Lin Zhang ◽  
Xin Geng ◽  
Jia Ge ◽  
Haifang Liu ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Fluorescent Probe ◽  
Carbon Dots ◽  
Turn On ◽  
Specific Determination ◽  
Ascorbic Acid Detection

A rapid turn-on fluorescent probe is proposed for the sensitive and specific determination of ascorbic acid based on carbon dots–MnO2 nanocomposites.

N,S co-doped carbon dots based fluorescent “on-off-on” sensor for determination of ascorbic acid in common fruits

2018 ◽  
Vol 258 ◽  
pp. 214-221 ◽  
Author(s):  
Xueli Luo ◽  
Wengang Zhang ◽  
Yong Han ◽  
Xiumei Chen ◽  
Li Zhu ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Carbon Dots ◽  
Doped Carbon Dots ◽  
Co Doped
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