scholarly journals Voltammetric Determination of Amoxicillin Using a Reduced Graphite Oxide Nanosheet Electrode

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Thi Hai Yen Pham ◽  
Thi Trang Mai ◽  
Hoang Anh Nguyen ◽  
Thi Thu Hien Chu ◽  
Thi Thu Ha Vu ◽  
...  
Keyword(s):  
Graphite Oxide ◽  
Graphite Electrode ◽  
Limit Of Detection ◽  
Reduction Process ◽  
Stripping Voltammetry ◽  
Active Surface ◽  
Active Surface Area ◽  
Accumulation Time ◽  
Reduced Graphite Oxide

A reduced graphite oxide nanosheet electrode (RGOnS) was prepared as a sensor for amoxicillin (AMX) detection, an antibiotic commonly used in the livestock farm, by the square-wave adsorptive stripping voltammetry technique. Graphite oxide with nanosheet shape was produced from a graphite electrode by a chronoamperometry process at 5 V and then an electrochemical reduction process was carried out to form RGOnS with restored long-range conjugated networks and better conductivity. The electrodes were characterized by SEM, EDX, and FTIR spectroscopy. The RGOnS electrode prepared at an optimal reduction potential of −1 V for 120 s exhibits a larger electrochemical active surface area, and the obtained oxidation signal of AMX is approximately ten times higher than that of the pristine graphite electrode. The analytical conditions such as the pH of electrolyte and accumulation time were optimized. The calibration curve built under the optimal conditions provided a good linear relationship in the range of AMX concentration from 0.5–80 µM with the correlation coefficient of 0.9992. The limit of detection was calculated as 0.193 µM. Satisfactory results are obtained from the detection of the AMX in different samples using the prepared electrode.

scholarly journals Determination of Carmine Food Dye (E120) in Foodstuffs by Stripping Voltammetry

2009 ◽  
Vol 92 (5) ◽  
pp. 1454-1459 ◽  
Author(s):  
Ahmad H Alghamdi ◽  
Hamed M Alshammery ◽  
Mohamed A Abdalla ◽  
Ali F Alghamdi
Keyword(s):  
Supporting Electrolyte ◽  
Reduction Process ◽  
Stripping Voltammetry ◽  
Pulse Amplitude ◽  
Acetate Buffer ◽  
Experimental Conditions ◽  
Accumulation Time ◽  
Food Dye ◽  
Voltammetric Technique

Abstract The behavior of the food colorant agent carmine (E120) was studied by square-wave adsorptive stripping voltammetry (SW-AdSV) at the hanging mercury drop electrode. It was observed that carmine gave a sensitive stripping voltammetric peak at 350 mV in pH 3 acetate buffer. The cyclic voltammetric technique was also used to characterize the electrochemical reduction process of carmine. The adsorptive voltammetric signal was evaluated with respect to various experimental conditions, and the optimized values were supporting electrolyte, acetate buffer; buffer acidity, pH 3; dye concentration, 3 107 M; accumulation time, 150 s; accumulation potential, 0.2 V; scan rate, 300 mV/s; pulse amplitude, 185 mV; SW frequency, 20 Hz; working electrode area, 0.6 mm2; and convection rate, 2600 rpm. The SW-AdSV peak currents depended linearly on the concentration of carmine from 5 108 to 1.25 107 mol/L (r 0.99). A detection limit of 1.43 109 mol/L with an RSD of 2.2 and a mean recovery of 97.9 were obtained. Possible interferences by several substances usually present in food products such as food additive dyes (E102, E100, E123, E127, and E129), artificial sweeteners, preservatives, and antioxidants were also evaluated. The proposed electrochemical procedure was successfully applied to the determination of carmine food dye in spiked commercially available ice cream and soft drinks.

Determination of trace amounts of lead by adsorptive cathodic stripping voltammetry with L-3-(3,4-Dihydroxyphenyl)alanine

2009 ◽  
Vol 74 (4) ◽  
pp. 599-610 ◽  
Author(s):  
Mohammad Bagher Gholivand ◽  
Alireza Pourhossein ◽  
Mohsen Shahlaei
Keyword(s):  
Lead Concentration ◽  
Stripping Voltammetry ◽  
Optimum Conditions ◽  
Lead In Blood ◽  
Accumulation Time ◽  
Cathodic Stripping Voltammetry ◽  
Voltammetric Measurement ◽  
Adsorbed Complex ◽  
Reduction Current

A sensitive and selective procedure is presented for the voltammetric determination of lead. The procedure involves an adsorptive accumulation of lead L-3-(3,4-dihydroxyphenyl)alanine (LDOPA) on a hanging mercury drop electrode, followed by a stripping voltammetric measurement of reduction current of an adsorbed complex at –0.15 V (vs Ag|AgCl). Optimum conditions for lead analysis include pH 8.5, 80 μM LDOPA and accumulation potential –0.15 V (vs Ag|AgCl). The peak currents are proportional to the lead concentration 1–300 nmol l–1 with a detection limit of 0.6 nmol l–1 and accumulation time 60 s. The method was used for the determination of lead in blood, dry tea and also in waters.

scholarly journals First Electrochemical Method of Nitrothal-Isopropyl Determination in Water Samples

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Dariusz Guziejewski ◽  
Agnieszka Nosal-Wiercińska ◽  
Sławomira Skrzypek ◽  
Witold Ciesielski ◽  
Sylwia Smarzewska
Keyword(s):  
Environmental Samples ◽  
Electrochemical Method ◽  
Concentration Level ◽  
Stripping Voltammetry ◽  
Adsorptive Stripping Voltammetry ◽  
Hanging Mercury Drop Electrode ◽  
Optimal Conditions ◽  
Step Potential ◽  
Accumulation Time

The aim of the research was the use of square wave adsorptive stripping voltammetry (SWAdSV) in conjunction with a hanging mercury drop electrode (HMDE) for the determination of nitrothal-isopropyl. It was found that optimal SW technique parameters were frequency, 200 Hz; amplitude, 50 mV; and step potential, 5 mV. Accumulation time and potential were studied to select the optimal conditions in adsorptive stripping voltammetry: 45 s at 0.0 V, respectively. The calibration curve (SWSV) was linear in the nitrothal-isopropyl concentration range from 2.0 × 10−7 to 2.0 × 10−6 mol L−1 with detection limit of 3.46 × 10−8 mol L−1. The repeatability of the method was determined at a nitrothal-isopropyl concentration level equal to 6.0 × 10−7 mol L−1 and expressed as RSD = 5.5% (n=6). The proposed method was successfully validated by studying the recovery of nitrothal-isopropyl in spiked environmental samples.

scholarly journals Microfabricated Au-Film Sensors for the Voltammetric Determination of Hg(II)

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 1518
Author(s):  
Maria Tsetsoni ◽  
Eleni Roditi ◽  
Christos Kokkinos ◽  
Anastasios Economou
Keyword(s):  
Electrode Surface ◽  
Limit Of Detection ◽  
Anodic Stripping Voltammetry ◽  
Stripping Voltammetry ◽  
Voltammetric Determination ◽  
Film Sensor ◽  
Au Film ◽  
Working Electrode ◽  
Anodic Stripping

In this work, a microfabricated Au-film sensor was designed and fabricated for thevoltammmetric determination of Hg(II). The electrode was fabricated on a silicon chip with astandard microengineering approach utilizing photolithography for patterning the electrode shapeand sputtering for deposition of thin Cr and Au films on the surface of the sensors. The sensorswere used for the determination of trace Hg(II) with anodic stripping voltammetry (ASV): initiallyHg(II) in the sample was accumulated on the Au working electrode surface by reduction andformation of an Au(Hg) amalgam followed by oxidation of the preconcentrated metallic Hg using asquare wave voltammetric scan. The limit of detection was 1.5μgL−1 and the coefficient of variationof 10 consecutive measurements was 3.1%.

Metallic Film Modified Screen-Printed Carbon Electrode for Determination of 17α-Methyltestosterone

2019 ◽  
Vol 824 ◽  
pp. 182-189
Author(s):  
Chim Math ◽  
Wijitar Dungchai ◽  
Sudtida Pliankarom Thanasupsin
Keyword(s):  
Modified Electrode ◽  
Limit Of Detection ◽  
Diffusion Mechanism ◽  
Modified Electrodes ◽  
Active Surface ◽  
Deposition Potential ◽  
Active Surface Area ◽  
Male Population ◽  
Screen Printed Carbon Electrode ◽  
Screen Printed

17α-methyltestosterone (MT) is a synthetic androgen. It is used widely for inducing an all-male population of Nile tilapia (Oreochromis niloticus). In this work, the detection of MT was conducted using screen-printed carbon electrodes (SPCE). These were a bare electrode, a bismuth modified electrode (Bi-SPCE) and an antimony modified electrode (Sb-SPCE). The successful electrode modification was confirmed by scanning electron microscopy. The electroanalytical performance of the SPCE modified electrodes for MT detection was examined by cyclic voltammetry. The highest active surface area of 1.073x10-4 cm2 was obtained on Sb-SPCE. This indicates that Sb-SPCE can enhance the sensitivity of MT detection better than the bare-SPCE and the Bi-SPCE. The Sb-SPCE showed a linear response for MT concentrations ranging from 2 to 8 mg.L-1. The sensitivity obtained from the slope of a calibration curve was -0.452 mA.mol-1.L-1 in a Britton-Robinson buffer pH 4.0 containing Sb 16 mg.L-1 with deposition potential and deposition time of 1 V and 90 seconds, respectively. A linear relationship between the square root of the scan rate and the peak current revealed that mass transfer of MT to the electrode was driven by a diffusion mechanism. The limit of detection was found to be 1 mg.L-1.

scholarly journals Sensitive Electrochemical Detection of Caffeic Acid in Wine Based on Fluorine-Doped Graphene Oxide

Sensors ◽  
2019 ◽  
Vol 19 (7) ◽  
pp. 1604 ◽  
Author(s):  
Venkatesh Manikandan ◽  
Boopathi Sidhureddy ◽  
Antony Thiruppathi ◽  
Aicheng Chen
Keyword(s):  
Graphene Oxide ◽  
Electrochemical Sensor ◽  
Caffeic Acid ◽  
Photoelectron Spectroscopy ◽  
Limit Of Detection ◽  
Active Surface ◽  
Differential Pulse ◽  
Active Surface Area ◽  
Food And Beverage ◽  
Doped Graphene

We report here a novel electrochemical sensor developed using fluorine-doped graphene oxide (F-GO) for the detection of caffeic acid (CA). The synthesized graphene oxide (GO) and F-GO nanomaterials were systematically characterized with a scanning electron microscope (SEM), and the presence of semi-ionic bonds was confirmed in the F-GO using X-ray photoelectron spectroscopy. The electrochemical behaviours of bare glassy carbon electrode (GCE), F-GO/GCE, and GO/GCE toward the oxidation of CA were studied using cyclic voltammetry (CV), and the results obtained from the CV investigation revealed that F-GO/GCE exhibited the highest electrochemically active surface area and electrocatalytic activity in contrast to the other electrodes. Differential pulse voltammetry (DPV) was employed for the analytical quantitation of CA, and the F-GO/GCE produced a stable oxidation signal over the selected CA concentration range (0.5 to 100.0 μM) with a low limit of detection of 0.018 μM. Furthermore, the acquired results from the selectivity studies revealed a strong anti-interference capability of the F-GO/GCE in the presence of other hydroxycinnamic acids and ascorbic acid. Moreover, the F-GO/GCE offered a good sensitivity, long-term stability, and an excellent reproducibility. The practical application of the electrochemical F-GO sensor was verified using various brands of commercially available wine. The developed electrochemical sensor successfully displayed its ability to directly detect CA in wine samples without pretreatment, making it a promising candidate for food and beverage quality control.

scholarly journals Chemical Detection by Analyte-Induced Change in Electrophoretic Deposition of Gold Nanoparticles

2021 ◽  
Author(s):  
Badri Mainali ◽  
Francis Patrick Zamborini
Keyword(s):  
Electrophoretic Deposition ◽  
Indium Tin Oxide ◽  
Negative Charge ◽  
Limit Of Detection ◽  
Anodic Stripping Voltammetry ◽  
Stripping Voltammetry ◽  
Au Nps ◽  
Hydronium Ions ◽  
Glass Electrodes

Abstract The electrophoretic deposition (EPD) of citrate-stabilized Au nanoparticles (cit-Au NPs) occurs on indium tin oxide (ITO)-coated glass electrodes upon electrochemical oxidation of hydroquinone (HQ) due to the release of hydronium ions. Anodic stripping voltammetry (ASV) for Au oxidation allows the determination of the amount of Au NP deposition under a specific EPD potential and time. The binding of Cr3+ to the cit-Au NPs inhibits the EPD by inducing aggregation and/or reducing the negative charge, which could lower the effective NP concentration of the cit-Au NPs and/or lower the electrophoretic mobility. This lowers the Au oxidation charge in the ASV, which acts as an indirect signal for Cr3+. The binding of melamine to cit-Au NPs similarly leads to aggregation and/or lowers the negative charge, also resulting in reduction of the ASV Au oxidation peak. The decrease in Au oxidation charge measured by ASV increases linearly with increasing Cr3+ and melamine concentration. The limit of detection (LOD) for Cr3+ is 21.1 ppb and 16.0 ppb for 15.1 and 4.1 nm diameter cit-Au NPs, respectively. Improving the sensing conditions allows for as low as 1 ppb detection of Cr3+. The LOD for melamine is 45.7 ppb for 4.1 nm Au NPs.

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