scholarly journals Gold Nanoparticles/Carbon Nanotubes and Gold Nanoporous as Novel Electrochemical Platforms for L-Ascorbic Acid Detection: Comparative Performance and Application

Chemosensors ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 229
Author(s):  
Cristina Tortolini ◽  
Federico Tasca ◽  
Mary Anna Venneri ◽  
Cinzia Marchese ◽  
Riccarda Antiochia
Keyword(s):  
Carbon Nanotubes ◽  
Ascorbic Acid ◽  
Gold Electrode ◽  
Electrochemical Sensors ◽  
Electrochemical Impedance ◽  
Acid Oxidation ◽  
Comparative Performance ◽  
Bare Gold Electrode ◽  
Ascorbic Acid Detection ◽  
Bare Gold

Herein, the effects of nanostructured modifications of a gold electrode surface in the development of electrochemical sensors for L-ascorbic acid detection have been investigated. In particular, a bare gold electrode has been modified by electrodeposition of gold single-walled carbon nanotubes (Au/SWCNTs) and by the formation of a highly nanoporous gold (h-nPG) film. The procedure has been realized by sweeping the potential between +0.8 V and 0 V vs. Ag/AgCl for 25 scans in a suspension containing 5 mg/mL of SWCNTs in 10 mM HAuCl4 and 2.5 M NH4Cl solution for Au/SWCNTs modified gold electrode. A similar procedure was applied for a h-nPG electrode in a 10 mM HAuCl4 solution containing 2.5 M NH4Cl, followed by applying a fixed potential of −4 V vs. Ag/AgCl for 60 s. Cyclic voltammetry and electrochemical impedance spectroscopy were used to characterize the properties of the modified electrodes. The developed sensors showed strong electrocatalytic activity towards ascorbic acid oxidation with enhanced sensitivities of 1.7 × 10−2 μA μM−1cm−2 and 2.5 × 10−2 μA μM−1cm−2 for Au/SWCNTs and h-nPG modified electrode, respectively, compared to bare gold electrode (1.0 × 10−2 μA μM−1cm−2). The detection limits were estimated to be 3.1 and 1.8 μM, respectively. The h-nPG electrode was successfully used to determine ascorbic acid in human urine with no significant interference and with satisfactory recovery levels.

scholarly journals Highly Selective Determination of Dopamine in the Presence of Ascorbic Acid and Serotonin at Glassy Carbon Electrodes Modified with Carbon Nanotubes Dispersed in Polyethylenimine

2008 ◽  
Vol 8 (11) ◽  
pp. 6003-6009 ◽  
Author(s):  
Marcela C. Rodríguez ◽  
María D. Rubianes ◽  
Gustavo A. Rivas
Keyword(s):  
Carbon Nanotubes ◽  
Ascorbic Acid ◽  
Glassy Carbon ◽  
Carbon Electrodes ◽  
Acid Oxidation ◽  
Promising Alternative ◽  
Glassy Carbon Electrodes ◽  
Multi Wall Carbon Nanotubes ◽  
Selective Determination

We report the highly selective and sensitive voltammetric dopamine quantification in the presence of ascorbic acid and serotonin by using glassy carbon electrodes modified with a dispersion of multi-wall carbon nanotubes (MWCNT) in polyethylenimine, PEI (GCE/MWCNT-PEI). The electrocatalytic activity of the MWCNT deposited on the glassy carbon electrode has allowed an important decrease in the overvoltages for the oxidation of ascorbic acid and dopamine, making possible a clear definition of dopamine, serotonin and ascorbic acid oxidation processes. The sensitivities for dopamine in the presence and absence of 1.0 mM ascorbic acid and serotonin were (2.18±0.03 × 105 μAM−1 (r = 0.9998); and (2.10±0.07 × 105 μAM−1 (r = 0.9985), respectively, demonstrating the excellent performance of the GCE/MWCNT-PEI. The detection limit for dopamine in the mixture was 9.2 × 10−7 M. The R. S. D. for the determination of 50 μM dopamine using four different electrodes was 3.9% when modified with the same MWCNT/PEI dispersion, and 4.6% when using four different dispersions. The modified electrode has been successfully applied for recovery assays of dopamine in human blood serum. Therefore, the new sensor represents an interesting and promising alternative for the electrochemical quantification of neurotransmitters and other analytes of clinical interest.

THE ELECTROCHEMICAL STUDY OF SELF-ASSEMBLED 1,3-PROPANEDITHIOL ON GOLD

2007 ◽  
Vol 14 (01) ◽  
pp. 111-115
Author(s):  
YUQING MIAO ◽  
JIANRONG CHEN ◽  
XIAOHUA WU ◽  
KEMING FANG
Keyword(s):  
Gold Electrode ◽  
Modified Electrodes ◽  
Gold Surface ◽  
Electrochemical Study ◽  
Potential Range ◽  
Electrochemical Behaviors ◽  
Bare Gold Electrode ◽  
Self Assembled ◽  
Bare Gold

The electrochemical behaviors of bare/dithiol-modified gold electrode were studied in the PBS solution with/without dithiols. A pair of current peaks between -1.4 and -0.5 V is related to dithiol adsorption or re-adsorption. An oxidative peak at 0.37 V accompanied by a slight peak at 0.03 V is observed between -0.5 and 0.7 V for the bare gold electrode in the thiol solution, which is due to the formation of bilayer. When the potential is scanned to a very positive value at 1.2 V, a new oxidative peak at 1.07 V appears for the bare gold electrode in the dithiol solution or the PBS solution. The assembled dithiols are desorbed, and gold surface is exposed. The study indicates that the 1,3-propanedithiol modified electrodes should be used during the potential range of -0.8 to 0.8 V to keep the assembled layer stable.

Design of Electrochemical Biosensor on Naphthalene Content Detection in Water Based on SCM

2014 ◽  
Vol 597 ◽  
pp. 435-438
Author(s):  
Yuan Liu ◽  
Ya Ping Yu ◽  
Hai Yun Wu ◽  
Ruo Kui Chang
Keyword(s):  
Rapid Detection ◽  
Gold Electrode ◽  
Electrochemical Biosensor ◽  
Electrochemical System ◽  
Display Unit ◽  
Oxidation Reduction ◽  
Water Based ◽  
Bare Gold Electrode ◽  
Data Acquisition And Processing ◽  
Bare Gold

In order to achieve rapid detection of naphthalene content in water, the electrochemical biosensor has been developed based on microcontroller by the cyclic voltammetry (CV). The system is consisted of a three-electrode electrochemical system, converting circuit, IAP15F2K61S2 microcontroller and display unit. The voltammetric oxidation-reduction response of a bare gold electrode has been gained in a potential window from −0.3 V to +0.6V. After data acquisition and processing, according to the change of peak current of voltammograms, the naphthalene content is detected and displayed.the sensor can finish the detection of naphthalene content in 15 minutes.

scholarly journals Bi2S3/rGO Composite Based Electrochemical Sensor for Ascorbic Acid Detection

Chemosensors ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 190
Author(s):  
Chengling Qu ◽  
He Li ◽  
Shuang Zhou ◽  
Guodong Li ◽  
Cheng Wang ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Graphene Oxide ◽  
Electrochemical Sensor ◽  
Electrochemical Impedance ◽  
Facile Hydrothermal Method ◽  
Reduced Graphene ◽  
Catalytic Sites ◽  
Ascorbic Acid Detection ◽  
Enhanced Electrochemical Performance ◽  
Eis Analysis

The engineering of an efficient electrochemical sensor based on a bismuth sulfide/reduced graphene oxide (Bi2S3/rGO) composite to detect ascorbic acid (AA) is reported. The Bi2S3 nanorods/rGO composite was synthesized using a facile hydrothermal method. By varying the amount of graphene oxide (GO) added to the synthesis, the morphology and size of Bi2S3 nanorods anchored on the surface of rGO can be tuned. Compared to a bare glassy carbon electrode (GCE), the GCE modified with Bi2S3/rGO composite presented enhanced electrochemical performance, which was attributed to the optimal electron transport between the rGO support and the loaded Bi2S3 as well as to an increase in the number of active catalytic sites. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) analysis of Bi2S3/rGO/GCE demonstrate that the active Bi2S3/rGO layer on GCE plays an important role in the electrochemical behavior of the sensor. In particular, the Bi2S3/rGO/GCE sensor shows a wide detecting range (5.0–1200 μM), low detection limit (2.9 µM), good sensitivity (268.8 μA mM−1 cm−2), and sufficient recovery values (97.1–101.6%) for the detection of ascorbic acid.

scholarly journals OPTIMISATION OF AN ELECTROCHEMICAL SENSOR BASED ON BARE GOLD ELECTRODE FOR DETECTION OF ALUMINIUM ION

2020 ◽  
pp. 103
Author(s):  
Gilbert Ringgit ◽  
Shafiquzzaman Siddiquee ◽  
Suryani Saallah ◽  
Mohammad Tamrin Mohamad Lal
Keyword(s):  
Heavy Metal ◽  
Metal Ion ◽  
Gold Electrode ◽  
Heavy Metal Ion ◽  
Optimum Conditions ◽  
Accumulation Time ◽  
Aluminium Ion ◽  
Scan Rate ◽  
Bare Gold Electrode ◽  
Bare Gold

In this work, an electrochemical method for detection of trace amount of aluminium (Al3+), a heavy metal ion, based on a bare gold electrode (AuE) was developed. Current responses of the AuE under various type of electrolytes, redox  indicators, pH, scan rate and accumulation time were investigated using cyclic voltammetry (CV) method to obtain the optimum conditions for Al3+ detection. The sensing properties of the AuE towards the target ion with different concentrations were investigated using differential pulse voltammetry (DPV) method. From the CV results, the optimalconditions for the detection of Al3+ were Tris-HCl buffer (0.1 M, pH 2) supported by 5 mM Prussian blue with scan rate and accumulation time respectively of 100 mVs−1 and 15 s. Under the optimum conditions, the DPV method was detected with different concentrations of aluminium ion ranging from 0.2 to 1.0 ppm resulted in a good linear regression r² = 0.9806. This result suggests that the optimisation of the basic parameters in electrochemical detection using AuE is crucial before further modification of the Au-electrode to improve the sensitivity and selectivity especially for the low concentration of ion detection. The developed method has a great potential for rapid detection of heavy metal ion (Al3+) in drinking water samples.

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