scholarly journals Poly (Orange CD) sensor for paracetamol in presence of folic acid and dopamine

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
S. D. Sukanya ◽  
B. E. Kumara Swamy ◽  
J. K. Shashikumara ◽  
S. C. Sharma ◽  
S. A. Hariprasad
Keyword(s):  
Folic Acid ◽  
Phosphate Buffer Solution ◽  
High Sensitivity ◽  
Cost Effective ◽  
Selective Detection ◽  
Oxidation Peak ◽  
Buffer Solution ◽  
Peak Separation ◽  
Rate Study ◽  
Electro Oxidation

AbstractIn the present work, Orange CD was chosen as an intriguing modifier for the electropolymerization on the surface of CPE by the CV technique. A novel, sensitive, and cost-effective poly (Orange CD) MCPE (PoOCD/MCPE) sensor was utilized for the selective detection of paracetamol (PA) in 0.2 M phosphate buffer solution (PBS) of pH 7.4. The oxidation peak current of PA was vastly enhanced at the sensor. The scan rate study is suggested that electro-oxidation of PA was adsorption-controlled. The pH study testifies the redox pathways transport with the same quantity of electrons and protons. The detection limit of PA is found to be 2.64 µM. DPV results show that substantial peak separation between PA, folic acid (FA), and dopamine (DA) could be facilitating their individual and simultaneous determination on the sensor. The decorated sensor demonstrates high sensitivity, stability, reproducibility, repeatability and has been successfully exploited for the detection of PA in a tablet with promising results.

Electro-oxidation of captopril at a gold electrode and its determination in pharmaceuticals and human fluids

2015 ◽  
Vol 7 (20) ◽  
pp. 8673-8682 ◽  
Author(s):  
Nagaraj P. Shetti ◽  
Shweta J. Malode ◽  
Sharanappa T. Nandibewoor
Keyword(s):  
Gold Electrode ◽  
Phosphate Buffer Solution ◽  
Differential Pulse ◽  
Chemical Parameters ◽  
Buffer Solution ◽  
Solution Ph ◽  
Physico Chemical ◽  
Electro Oxidation ◽  
Pulse Voltammetry ◽  
Human Fluids

Gold electrode was used for the oxidation of captopril in phosphate buffer solution pH 3.6 to study the influence of several physico-chemical parameters like potential, scan rate, pH and concentration by cyclic, linear sweep and differential pulse voltammetry.

scholarly journals Online Coupling of Lab-on-Valve Format to Amperometry Based on Polyvinylpyrrolidone-Doped Carbon Paste Electrode and Its Application to the Analysis of Morin

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Yang Wang ◽  
Guojun Yao ◽  
Jie Tang ◽  
Chun Yang ◽  
Qin Xu ◽  
...  
Keyword(s):  
Carbon Paste Electrode ◽  
Supporting Electrolyte ◽  
Phosphate Buffer Solution ◽  
Current Response ◽  
Oxidation Peak ◽  
Carbon Paste ◽  
Buffer Solution ◽  
Electrochemical Behaviors ◽  
Paste Electrode

The potential capabilities and analytical performance of lab-on-valve (LOV) manifold as a front end to amperometry have been explored for the on-line determination of morin. Meanwhile, the electrochemical behaviors of morin were investigated based on polyvinylpyrrolidone- (PVP-) doped carbon paste electrode (CPE), which found that PVP can significantly improve its oxidation peak current. The excellent amperometric current response was achieved when the potential difference (ΔE) of 0.6 V was implemented in pH 6.5 phosphate buffer solution (PBS) that served as the supporting electrolyte. A well-defined oxidation peak has been obtained in studies using PVP as a modifier of CPE based on the oxidation of morin. The present work introduces the LOV technique as a useful tool for amperometric measurement, documents advantages of using programmable flow, and outlines means for miniaturization of assays on the basis of PVP modified CPE. The proposed method was applied successfully to the determination of morin in real samples, and the spiked recoveries were satisfactory.

scholarly journals A novel dopamine electrochemical sensor based on La3+/ZnO nanoflower modified graphite screen printed electrode

2019 ◽  
Vol 9 (3) ◽  
pp. 187-195 ◽  
Author(s):  
Somayeh Tajik ◽  
Hadi Beitollahi ◽  
Mohammad Reza Aflatoonian
Keyword(s):  
Modified Electrode ◽  
Phosphate Buffer Solution ◽  
High Sensitivity ◽  
Differential Pulse ◽  
Electrochemical Determination ◽  
Screen Printed Electrode ◽  
Buffer Solution ◽  
Optimized Conditions ◽  
Screen Printed

Flower-like La3+/ZnO nanocomposite was facile synthesized. A simple and ultrasensitive sensor based on graphite screen printed electrode (SPE) modified by La3+/ZnO nanoflower was developed for the electrochemical determination of dopamine. The electrochemical behavior of dopamine was studied in 0.1 M phosphate buffer solution (PBS) using cyclic voltammetry (CV), chronoamperometry (CA) and differential pulse voltammetry (DPV). Compared with the unmodified graphite screen printed electrode, the modified electrode facilitates the electron transfer of dopamine, since it notably increases the oxidation peak current of dopamine. Also, according to CV results the maximum oxidation of dopamine on La3+/ZnO/SPE occurs at 150 mV which is about 140 mV more negative compared with unmodified SPE. Under optimized conditions, the modified electrode exhibited a linear response over the concentration range from 0.15 to 300.0 μM, with a detection limit of 0.08 μM (S/N = 3). The proposed sensor exhibited a high sensitivity, good stability and was successfully applied for dopamine determination in dopamine ampoule, with high recovery.

Glucose electro-oxidation on Pt(100) in phosphate buffer solution (pH 7): A mechanistic study

2020 ◽  
Vol 354 ◽  
pp. 136765 ◽  
Author(s):  
Gisele A.B. Mello ◽  
William Cheuquepán ◽  
Valentín Briega-Martos ◽  
Juan M. Feliu
Keyword(s):  
Phosphate Buffer ◽  
Phosphate Buffer Solution ◽  
Mechanistic Study ◽  
Buffer Solution ◽  
Solution Ph ◽  
Electro Oxidation

Nafion/Quercetin/Graphene Composite-Modified Glassy Electrode for Selective and Sensitive Detection of Dopamine

2013 ◽  
Vol 641-642 ◽  
pp. 841-844
Author(s):  
Dai Min Song ◽  
Jian Fei Xia ◽  
Zong Hua Wang ◽  
Yan Zhi Xia ◽  
Fei Fei Zhang ◽  
...  
Keyword(s):  
Modified Electrode ◽  
Phosphate Buffer Solution ◽  
Differential Pulse ◽  
Sensitive Detection ◽  
Carbon Electrode ◽  
Good Reproducibility ◽  
Oxidation Peak ◽  
Buffer Solution ◽  
Graphene Composite ◽  
Pulse Voltammetry

Glassy carbon electrode (GCE) was modified using graphene (G), quercetin (Qu) and Nafion in this sequence to fabricate Nafion-Qu-G composite-modified GCE (Nafion/Qu/G/GCE). The as-prepared modified electrode combining the advantages of Nafion, Qu and G was employed for the selective and sensitive detection of dopamine (DA) in the presence of ascorbic acid (AA) and uric acid (UA). Compared with GCE, Qu/GCE, G/GCE and Qu/G/GCE, the Nafion/Qu/G/GCE was more electroactive and selective for DA. Differential pulse voltammetry (DPV) was used for electrochemical detection, the separations of the oxidation peak potentials for AA-DA and DA-UA were about 304 mV and 136 mV, which allowed selectively determining DA. In phosphate buffer solution (PBS) of pH 6.8, the Nafion/Qu/G/GCE provided a detection limit of 2.31×10-8 mol/L (S/N=3) for DA. Linearity (R=0.9963) of the peak currents against the concentration of DA was found over the range of 1.0×10-7 to 1.0×10-3 mol/L. Furthermore, the modified electrode exhibited good reproducibility and stability.

scholarly journals Study on the Highly Sensitive AChE Electrode Based on Multiwalled Carbon Nanotubes

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Shuping Zhang ◽  
Zhancheng Gu ◽  
Yongli Hu ◽  
Song Qu ◽  
Ying Liu
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Modified Electrode ◽  
Self Assembly ◽  
Phosphate Buffer Solution ◽  
High Sensitivity ◽  
Acetylcholine Esterase ◽  
Layer By Layer ◽  
Buffer Solution ◽  
Multiwalled Carbon

Using chitosan (CS) as carrier, the method named layer-by-layer (LBL) self-assembly modification to modify the glassy carbon electrode (GCE) with multiwalled carbon nanotubes (MWNTs) and acetylcholine esterase (AChE) was proposed to prepare the acetylcholine esterase electrode with high sensitivity and stability. The modified electrode was used to detect pesticide of aldicarb, and the enzyme inhibition rate of the electrode showed good linearity with pesticide concentrations in the range of 10−10 g·L−1to 10−3 g·L−1. The detection limit was 10−11 g·L−1. The modified electrode was also used to detect the actual sample, and the recovery rate range was from 97.72% to 107.15%, which could meet the rapid testing need of the aldicarb residue. After being stored in the phosphate buffer solution (PBS) in 4°C for 30 days, the modified electrode showed good stability with the response current that was 80% of the original current.

Selective Binding of Nucleobases and its Electrochemical Behavior at Glassy Carbon Electrode in PBS at pH 7.4

2011 ◽  
Vol 239-242 ◽  
pp. 328-333
Author(s):  
Jing Jie Cui ◽  
De Hui Sun ◽  
Hong Liu ◽  
Guan Cong Wang ◽  
Hong Shi Zhao ◽  
...  
Keyword(s):  
Glassy Carbon Electrode ◽  
Glassy Carbon ◽  
Electrochemical Behavior ◽  
Electrochemical Impedance ◽  
Electrochemical Behaviour ◽  
Phosphate Buffer Solution ◽  
Carbon Electrode ◽  
Oxidation Peak ◽  
Buffer Solution ◽  
Selective Binding

The electrochemical behavior of nucleobases has been studied in 0.1 M phosphate buffer solution (PBS), pH 7.4 without removing oxygen, using glassy carbon electrode (GCE). Cyclic voltammetry (CV), electrochemical impedance experiment (EIS) and square wave voltammetry (SWV) were employed in the measurements of the nucleobases electrochemical signals at GCEs. Guanine (G) and adenine (A) produced well-defined oxidation peaks at about +0.66 and +0.96 V under the CV sweep at 100 mV/s, respectively. SWV was particularly useful in investigating the electrochemical behaviour of pyrimidine bases. In the SWV detection, thymine (T) clearly appeared an oxidation peak at 1.1 V, while cytosine (C) and uracil (U) did a complex oxidation peak at 1.3 V. Nucleobases possess an irreversible and adsorption-controlled electrochemical process at GCEs in 0.1 M PBS (pH 7.4). The average surface concentrations (Γ) of G and A on the surface of the GCE were estimated to be about 1.6515×10−10and 8.8232×10−11mol/cm2, respectively. Due to the selective interactions of nucleobases with each other, the nucleobase oxidation peaks shift and new oxidation peaks appeared. The new oxidation peaks at +1.62 and 1.55 V may correspond to the oxidation of GC pairs and AT pairs, respectively. The detection of the electrochemical behaviour and selective binding of nucleobases in a physiological PBS at pH 7.4 is of particular interest for electrochemical sensor applications in physiological media.

scholarly journals Modified graphite electrodes as potential cathodic electrocatalysts for microbial electrolysis cells

2019 ◽  
Vol 51 (2) ◽  
pp. 284-288
Author(s):  
E. Chorbadzhiyska ◽  
I. Bardarov ◽  
Y. Hubenova ◽  
M. Mitov
Keyword(s):  
Phosphate Buffer Solution ◽  
Modified Electrodes ◽  
Linear Sweep Voltammetry ◽  
Cost Effective ◽  
Innovative Technology ◽  
Electrolysis Cell ◽  
High Catalytic Activity ◽  
Buffer Solution ◽  
Graphite Electrodes ◽  
Microbial Electrolysis

Microbial electrolysis cell (MEC) is an ecologically clean and innovative technology for hydrogen production. The development of cost-effective cathodes with high catalytic activity for hydrogen evolution reaction (HER) in nearneutral electrolytes is the most critical challenge for the practical application of MEC technology. In this study, graphite electrodes, functionalized with non-noble metal oxides, were produced and after electrochemical pre-treatment investigated as potential cathodes for MEC. The morphology of the developed materials was analyzed by scanning electron microscopy (SEM). Their electrochemical performance in neutral phosphate buffer solution (PBS) was explored by means of linear sweep voltammetry (LSV) and chronoamperometry (CA). The results from both methods show that all modified electrodes exhibit higher electrocatalytic activity towards HER than that of bare graphite, which is a prerequisite for further evaluation of these materials as cathodes in real MEC.

Synthesis and characterisation of a novel bi-nuclear copper2+ complex and its application as electrode-modifying agent for simultaneous voltammetric determination of dopamine and ascorbic acid

2014 ◽  
Vol 68 (2) ◽  
Author(s):  
Diganta Das ◽  
Babita Sarma ◽  
Sangita Haloi
Keyword(s):  
Ascorbic Acid ◽  
Modified Electrode ◽  
Phosphate Buffer Solution ◽  
Oxidation Potential ◽  
Buffer Solution ◽  
Electrode Potentials ◽  
Electro Oxidation ◽  
Simultaneous Voltammetric Determination ◽  
Complex Ion

AbstractA new binuclear complex of copper2+, [LCu2+(CH3COO)2Cu2+L](CH3COO)2 where L is N,N-bis(phthalimide)ethylenediamine, was synthesised and characterised. The complex ion [LCu2+ (CH3COO)2Cu2+L]2+ was encapsulated into ZSM-5 zeolite and used to modify the surface of the glassy carbon electrode. This modified electrode, in a phosphate buffer solution at pH 7.0, exhibited an oxidation potential for dopamine (DA) and ascorbic acid (AA) at electrode potentials of 0.230 V and −0.090 V vs. Ag/AgCl respectively, a separation of 0.320 V. The electro-oxidation of DA or AA on the modified electrode is independent of each other. No interference was observed from Na+, K+, Cl−, SO42−, Mg2+, Ca2+, Zn2+, Fe2+, and glucose. The detection limits obtained were 2.91 × 10−7 M for DA and 3.5 × 10−7 M for AA.

scholarly journals One-Step Electrodeposition Synthesized Aunps/Mxene/ERGO for Selectivity Nitrite Sensing

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1892
Author(s):  
Tan Wang ◽  
Cong Wang ◽  
Xianbao Xu ◽  
Zhen Li ◽  
Daoliang Li
Keyword(s):  
Phosphate Buffer Solution ◽  
Oxidation Peak ◽  
Applied Potential ◽  
X Ray Diffraction ◽  
Buffer Solution ◽  
Solution Ph ◽  
X Ray ◽  
Long Term Stability ◽  
One Step

In this paper, a new nanocomposite AuNPs/MXene/ERGO was prepared for sensitive electrochemical detection of nitrite. The nanocomposite was prepared by a facile one-step electrodeposition, HAuCl4, GO and MXene mixed in PBS solution with the applied potential of –1.4 V for 600 s. The modified material was characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and cyclic voltammetry (CV). The electrochemical behavior of nitrite at the modified electrode was performed by CV and chronoamperometry. The AuNPs/MXene/ERGO/GCE showed a well-defined oxidation peak for nitrite at +0.83 V (Vs. Ag/AgCl) in 0.1 M phosphate buffer solution (pH 7). The amperometric responses indicated the sensor had linear ranges of 0.5 to 80 μM and 80 to 780 μM with the LOD (0.15 μM and 0.015 μM) and sensitivity (340.14 and 977.89 μA mM–1 cm–2), respectively. Moreover, the fabricated sensor also showed good selectivity, repeatability, and long-term stability with satisfactory recoveries for a real sample. We also propose the work that needs to be done in the future for material improvements in the conclusion.

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