scholarly journals Gold Electrodes Modified with Self-Assembled Layers Made of Sulphur Compounds and Gold Nanoparticles Used for Selective Electrocatalytic Oxidation of Catecholamine in the Presence of Interfering Ascorbic and Uric Acids

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Teresa Łuczak
Keyword(s):  
Gold Nanoparticles ◽  
Detection Limit ◽  
Electrocatalytic Oxidation ◽  
Modified Electrodes ◽  
Gold Electrodes ◽  
Current Response ◽  
Good Sensitivity ◽  
Sulphur Compounds ◽  
Peak Separation

Gold electrodes modified with S-containing compounds and gold nanoparticles were used for determination of epinephrine (EP) in aqueous solution. The modified electrodes exhibited a good sensitivity, reproducibility, and stability. The results have shown that modified electrodes could clearly resolve the oxidation peaks of epinephrine, ascorbic acid (AA), and uric acid (UA) with peak-to-peak separation enabling determination of EP, AA, and UA in their simultaneous presence. A linear relationship between EP concentration and current response was obtained in the range of 0.1 μM to 700 μM with the detection limit ≥0.034 μM for the electrodes modified at 2D template and in the range of 0.1 μM to 800 μM with the detection limit ≥0.030 μM for the electrodes modified at 3D template.

scholarly journals Electrochemical determination of ascorbic acid at p-phenylenediamine film-holes modified glassy carbon electrode

2015 ◽  
Vol 80 (9) ◽  
pp. 1161-1175 ◽  
Author(s):  
Bikila Olana ◽  
Shimeles Kitte ◽  
Tesfaye Soreta
Keyword(s):  
Ascorbic Acid ◽  
Detection Limit ◽  
Glassy Carbon Electrode ◽  
Modified Electrode ◽  
Glassy Carbon ◽  
Linear Response ◽  
Modified Electrodes ◽  
Electrochemical Determination ◽  
Carbon Electrode

In this work the determination of ascorbic acid (AA) at glassy carbon electrode (GCE) modified with a perforated film produced by reduction of diazonium generated in situ from p-phenylenediamine (PD) is reported. Holes were intentionally created in the modifier film by stripping a pre-deposited gold nanoparticles. The modified electrodes were electrochemically characterized by common redox probes: hydroquinone, ferrocyanide and hexamineruthenium(III). The cyclic voltammetric and amperometric response of AA using the modified electrodes was compared with that of bare GCE. The bare GCE showed a linear response to AA in the concentration range of 5 mM to 45 mM with detection limit of 1.656 mM and the modified GCE showed a linear response to AA in the concentration range of 5 ?M to 45 ?M with detection limit of 0.123 ?M. The effect of potential intereferents on amperometric signal of AA at the modified GCE was examined and found to be minimal. The inter-electrode reproducibility, stability, and accuracy were determined. The modified electrode showed excellent inter-electrode reproducibility, accuracy and stability. The modified electrode reported is a promising candidate for use in electroanalysis of AA.

scholarly journals Selective Determination of Iron(III) in Sea Water by Gold Nanoparticles Self-assembled with N-carboxyl- L-cysteine

2014 ◽  
Vol 17 (1) ◽  
pp. 001-004 ◽  
Author(s):  
Benzhi Liu ◽  
Min Wang
Keyword(s):  
Gold Nanoparticles ◽  
Detection Limit ◽  
Sea Water ◽  
Stripping Voltammetry ◽  
Differential Pulse ◽  
Operational Parameters ◽  
Selective Determination ◽  
Self Assembled ◽  
Optimized Conditions

Application of gold nanoparticles self-assembled with N-carboxyl- L-cysteine for the determination of iron(III) was investigated. Differential pulse adsorptive stripping voltammetry was used to detect iron(III). Various operational parameters were investigated and discussed in terms of their effects on the measurement signals. A linear range from 0.1 nM to 1.8 nM with a detection limit of 0.03 nMwas obtained under optimized conditions. The applicability of the method was successfully tested by determination of iron(III) in sea water samples.

The influence of gold nanoparticles on the electroactivity of nickel tetrasulfonated phthalocyanine

2014 ◽  
Vol 18 (08n09) ◽  
pp. 642-651 ◽  
Author(s):  
Audacity Maringa ◽  
Tebello Nyokong
Keyword(s):  
Gold Nanoparticles ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Glassy Carbon ◽  
Electrochemical Impedance ◽  
Modified Electrodes ◽  
Enhancement Effect ◽  
Carbon Electrode ◽  
Cathodic Peak ◽  
Peak Separation

We report on the electrodeposition of gold nanoparticles ( AuNPs ) on a glassy carbon electrode (GCE) followed by deposition of nickel tetrasulfonated phthalocyanine ( NiTSPc ) film by electropolymerization (poly- NiTSPc -GCE) to form Poly- NiTSPc / AuNPs -GCE. The presence of the gold nanoparticles caused a lowering of the anodic and cathodic peak separation (ΔE p ) of ferricyanide from 126 mV on poly- NiTSPc to 110 mV on poly- NiTSPc / AuNPs . The electrooxidation of nitrite improved on modified electrodes compared to GCE, with the latter giving E p = 0.78 V and the modified electrodes gave E p = 0.62 V or 0.61 V. Poly- NiTSPc / AuNPs -GCE had higher currents compared to poly- NiTSPc -GCE. This indicates the enhancement effect caused by the AuNPs . Electrochemical impedance spectroscopy and chronoamperometric studies also showed that poly- NiTSPc / AuNPs -GCE was a better electrocatalyst than poly- NiTSPc -GCE or AuNPs -GCE.

Detection of Anthracene in Real Water Samples with a Label-Free Amperometric Immunosenor

2011 ◽  
Vol 183-185 ◽  
pp. 547-551 ◽  
Author(s):  
Yan Zhang ◽  
Ping Ge Dian ◽  
Hui Sheng Zhuang
Keyword(s):  
Detection Limit ◽  
Prussian Blue ◽  
Water Samples ◽  
Gold Film ◽  
Polyclonal Antibodies ◽  
Current Response ◽  
Label Free ◽  
Long Term Stability

A label-free amperometric immunosenor for determination of anthracene was developed. Prussian blue was electrodeposited on the glassy carbon electrode and then modified with nanometer-size gold film to protect Prussian blue layer and immobilized anthracene polyclonal antibodies. The characteristics of the modified electrode at different stages of modification were studied by cyclic voltammetry. The performances of the amperometric immunosensor were studied in detail. At the optimal experimental condition, the current response of the immunosensor was proportional to the concentration of anthracene in the range of 1.8~90 ng•mL-1with a detection limit of 0.82 ng•mL-1(S/N=3). The studied immunosensor exhibited low detection limit, long-term stability and easy regenerated. This mothod was applied to the anthracene detection in river water samples with satisfied results.

Design of screen-printed bulk modified electrodes using anthraquinone–cysteamine functionalized gold nanoparticles and their application to the detection of dissolved oxygen

2015 ◽  
Vol 7 (5) ◽  
pp. 2020-2027 ◽  
Author(s):  
Ida Tiwari ◽  
Monali Singh ◽  
Mandakini Gupta ◽  
Jonathan P. Metters ◽  
Craig E. Banks
Keyword(s):  
Gold Nanoparticles ◽  
Dissolved Oxygen ◽  
Low Cost ◽  
Modified Electrodes ◽  
Functionalized Gold Nanoparticles ◽  
Screen Printed

We investigated the electroanalytical determination of dissolved oxygen using low-cost disposable screen-printed bulk modified electrodes based on nanostructures.

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