scholarly journals Nafion-coated cadmium pentacyanonitrosylferrate-modified glassy carbon electrode for detection of dopamine in biological samples

Bioimpacts ◽  
2017 ◽  
Vol 8 (4) ◽  
pp. 263-270
Author(s):  
Mohammad Johari-Ahar ◽  
Jaleh Barar ◽  
Pari Karami ◽  
Davoud Asgari ◽  
Soodabeh Davaran ◽  
...  
Keyword(s):  
Modified Electrode ◽  
Glassy Carbon ◽  
Biological Samples ◽  
Limit Of Detection ◽  
Biological Fluids ◽  
Modified Electrodes ◽  
Serum Samples ◽  
Selective Determination ◽  
Sensitivity And Selectivity

Introduction: Dopamine is one of the key neurotransmitters (NTs) in nature, which plays a crucial role in the mammalian central nervous system (CNS). Its selective determination in the biological fluids is an essential need in the field of biomedicine studies. Methods: In this work, an amperometric sensor was developed using Nafion-coated cadmium pentacyanonitrosylferrate (CdPCNF) modified glassy carbon (GC) electrode (Nafion|CdPCNF|GC electrode) as an electrocatalyst to detect dopamine (DA) in human serum samples. To develop this sensor, the surface of bare GC electrode was coated with the film of CdPCNF through an electropolymerization method and then the modified electrode was coated with Nafion to minimize interferences, especially those arising from the presence of anionic compounds. The electrocatalytic behavior of the modified electrodes was studied using the cyclic voltammetry and amperometry, and then the ability of the sensor for the determination of DA in synthetic and biological samples was investigated. Results: The modified electrode was showed a significant electrocatalytic activity for the oxidation of DA at pH 7.4. The limit of detection (LOD) was 0.7 µM and also no interference effects arose from ascorbic acid (AA), uric acid (UA) or the other biological NTs was observed in the DA detection using the modified Nafion|CdPCNF|GC electrode. Conclusion: In comparison with the bare electrode, the Nafion|CdPCNF|GC electrode could determine DA in the biological samples with adequate sensitivity and selectivity. Therefore, we propose that the modified electrode is utilizable as an amperometric DA sensor for the biological sample analysis.

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.

NiO–ZrO2 nanocomposite modified electrode for the sensitive and selective determination of efavirenz, an anti-HIV drug

RSC Advances ◽  
2015 ◽  
Vol 5 (50) ◽  
pp. 40057-40064 ◽  
Author(s):  
Neeta Thapliyal ◽  
Nadir S. E. Osman ◽  
Harun Patel ◽  
Rajshekhar Karpoormath ◽  
Rajendra N. Goyal ◽  
...  
Keyword(s):  
Modified Electrode ◽  
Biological Samples ◽  
Trace Analysis ◽  
Selective Determination ◽  
Highly Sensitive ◽  
Anti Hiv

A highly sensitive NiO–ZrO2 nanocomposite modified electrode was fabricated for trace analysis of efavirenz in pharmaceutical and biological samples.

scholarly journals Preparation and Application of Keggin Silicomolybdic acid Modified Electrode

2020 ◽  
Author(s):  
Miao Liu ◽  
Mingxuan Jia ◽  
Dong Hui Li
Keyword(s):  
Glassy Carbon Electrode ◽  
Modified Electrode ◽  
Glassy Carbon ◽  
Photoelectron Spectroscopy ◽  
Limit Of Detection ◽  
Differential Pulse ◽  
Carbon Electrode ◽  
X Ray ◽  
Linear Relationships

Abstract An innovative method for the determination of isoniazid tablets is studied through electrochemical method for the modification of glassy carbon electrode (GCE). Polyoxomolybdate, with stable structures, has not been widely used for the determination of substance. In this study, the mentioned polyoxomolybdate was characterized by Fourier transform infrared spectroscopy (FT-IR), UV-vis, X-ray diffraction (XRD), Atomic force microscope (AFM) and X-ray photoelectron spectroscopy (XPS), and used to modify the glassy carbon electrode. The electrochemical performance of the polyoxomolybdate@GCE was investigated with cyclic voltammetry (CV) and differential pulse voltammetry (DPV), compared with the unmodified electrode, the proposed polyoxomolybdate modified electrode exhibited strong electro-catalytic activities towards isoniazid (INH). Under the optimized conditions, there was linear relationships between the DPV peak currents and the concentrations in the range of 1 × 10 -7 g/L to 3 × 10 -7 g/L for INH (R 2 = 0.9979), with the limit of detection (LOD) of 0.024 μg/L (based on S/N = 3). The modified electrode has proper reproducibility (RSD < 5%), stability, response time (< 3 min) and lifetime (up to 6 days).

Voltammetry Determination of Cefotaxime on Zinc Oxide Nanorod Modified Electrode

2020 ◽  
Vol 17 (1) ◽  
pp. 40-46
Author(s):  
Vanitha Vasantharaghavan ◽  
Ravichandran Cingaram
Keyword(s):  
Zinc Oxide ◽  
Glassy Carbon Electrode ◽  
Modified Electrode ◽  
Glassy Carbon ◽  
Dynamic Range ◽  
Limit Of Detection ◽  
Accurate Determination ◽  
Voltammetric Determination ◽  
Carbon Electrode

Background: The Glassy Carbon Electrode (GCE) was modified with zinc oxide nanoparticles to enhance the electrocatalytic activity of the redox behavior of cefotaxime ion. ATOMIC Force Microscopy (AFM) photographic studies showed the nanorod like structure of the zinc oxide, which was coated uniformly on the electrode surface. Methods: The zinc oxide nanorod modified electrode was used as novel voltammetric determination of cefotaxime. The results of voltammetric behavior are satisfactory in the electro oxidation of cefotaxime, and exhibit considerable improvement compared to glassy carbon electrode. Results: Under the optimized experimental conditions, the ZnO nanorod modified electrode exhibit better linear dynamic range from 300 ppb to 700 ppb with lower limit of detection 200 ppb for the stripping voltammetric determination of cefotaxime. Conclusion: The pharmaceutical and clinical formulation of cefotaxime was successfully applied for accurate determination of trace amounts on ZnO nanomateials modified electrode.

scholarly journals Poly(4-amino-3-hydroxynaphthalene-1-sulfonic acid) modified glassy carbon electrode for square wave voltammetric determination of amoxicillin in four tablet brands

BMC Chemistry ◽  
2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Adane Kassa ◽  
Meareg Amare
Keyword(s):  
Glassy Carbon Electrode ◽  
Modified Electrode ◽  
Glassy Carbon ◽  
Sulfonic Acid ◽  
Current Response ◽  
Carbon Electrode ◽  
Modified Glassy Carbon Electrode ◽  
Serum Samples ◽  
Square Wave

Abstract Background Amoxicillin (AMX), which is one of the β-lactam antibiotics used in the treatment of bacterial infections, is known to have a serious mechanism of resistance necessitating continuous monitoring of its level in pharmaceutical and serum samples. Results In this study, we presented selective, accurate, and precise square wave voltammetric method based on poly(4-amino-3-hydroxynaphthalene-1-sulfonic acid) modified glassy carbon electrode (poly(AHNSA/GCE)) for determination of amoxicillin in four selected tablet brands. Appearance of a peak in the oxidative scan direction without a peak in the reductive direction of cyclic voltammograms of both bare GCE and poly(AHNSA/GCE) with four folds current and much reduced potential on the modified electrode showed catalytic property of the modifier towards oxidation of AMX. While cyclic voltammetric studies of effect of scan rate showed predominantly diffusion controlled oxidation of AMX with one electron participation, effect of pH revealed participation of protons and electrons in a 1:1 ratio. The square wave voltammetric peak current response of the modified electrode for AMX showed linear dependence on the concentration of the spiked standard AMX in the range 10–150 µmol L−1 with 9.9 nmol L−1 LOD. The AMX content of the studied tablet brands were found in the range 97.84–100.78% of the labeled value. Spike recovery results of 99.6–100.5%, and interference recovery results of 95.4–100.8% AMX in the presence of 50–200% of ampicillin and cloxicillin validated the applicability of the method for determination of amoxicillin in tablet formulation. Conclusion In contrast to the previously reported works on determination of amoxicillin, the present method showed an excellent performance making it a potential method for determination of amoxicillin in real samples including serum samples.

MoSx–Co3O4 Nanocomposite for Selective Determination of Ascorbic Acid

2021 ◽  
Vol 21 (4) ◽  
pp. 2595-2603
Author(s):  
Sidra Amin ◽  
Aneela Tahira ◽  
Amber Solangi ◽  
Ayman Nafady ◽  
Zafar Hussain Ibupoto
Keyword(s):  
Ascorbic Acid ◽  
Glassy Carbon Electrode ◽  
Glassy Carbon ◽  
Limit Of Detection ◽  
Active Surface Area ◽  
Carbon Electrode ◽  
Selective Determination ◽  
Practical Applications ◽  
Wide Range

Designing a nanocomposite with sensitive and selective determination of ascorbic acid is challenging task. It is possible through the exploitation of attractive features of nanoscience and nanotechnology for the synthesis of nanostructured materials. Herein, we report the decoration of nanoparticle of MoSx on the surface of Co3O4 nanowires by hydrothermal method. The MoSx nanoparticles shared the large surface on the Co3O4 nanowires, thus it supported in the development enzyme free ascorbic acid sensor. Non-enzymatic sensor based on MoSx-Co3O4 composite was found very selective for the determination of ascorbic acid (AA) in phosphate buffer solution of pH 7.4. The MoSx-Co3O4 nanocomposite was used to modify the glassy carbon electrode to measure AA from variety of practical samples. The MoSx-Co3O4 nanocomposite was used to modify the glassy carbon electrode and it has shown the attractive analytical features such as a low working potential +0.3 V, linear range of concentration from 100–7000 μM, low limit of detection 14 μM, and low limit of quantification (LOQ) of 42 μM. The developed sensor is highly selective and stable. Importantly, it was applied successfully for the practical applications such as detection of AA from grapefruit, tomato and lemon juice. The excellent electrochemical properties of fabricated MoSx-Co3O4 nanocomposite can be attributed to the increasing electro active surface area of MoSx. The presented nanocomposite is earth abundant, environment friendly and inexpensive and it holds promising features for the selective and sensitive determination of AA from practical applications. The nanocomposite can be capitalized into the wide range of biomedical applications.

scholarly journals Schiff-Based Fluorescent-ON Sensor L Synthesis and Its Application for Selective Determination of Cerium in Aqueous Media

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Maria Sadia ◽  
Jehangir Khan ◽  
Robina Naz ◽  
Muhammad Zahoor ◽  
Ezzat Khan ◽  
...  
Keyword(s):  
Metal Ion ◽  
Limit Of Detection ◽  
Fluorescent Sensor ◽  
Aqueous Media ◽  
High Sensitivity ◽  
Transition Metal Ions ◽  
Acetonitrile Solution ◽  
Selective Determination ◽  
Sensitivity And Selectivity

In the present study, a fluorescent sensor L for sensing of Ce3+ ion was designed and characterized by XRD, 1HNMR, and FTIR. Its fluorescence behavior towards metal ion was examined by fluorescence spectroscopy. Chelation-enhanced fluorescence was shown by the sensor L upon interaction with Ce3+ ion. This fluorescent sensor exhibits high sensitivity and selectivity towards Ce3+ ion in acetonitrile solution, forming 2 : 1 (L : M) complex as determined by Job’s plot. Association constant was found to be 1×107 M−1 estimated from the Benesi-Hildebrand plot. No significant interference was observed in the presence of other studied alkali, alkaline, and transition metal ions. A rapid response was observed when employed for the determination of Ce3+ ion in spiked water samples with a limit of detection equal to 3.4×10−8 M.

scholarly journals Potentiometric Signal Transduction for Selective Determination of 1-(3-Chlorophenyl)piperazine “Legal Ecstasy” Through Biomimetic Interaction Mechanism

Chemosensors ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 46
Author(s):  
Eman El-Naby
Keyword(s):  
Dynamic Range ◽  
Limit Of Detection ◽  
Interaction Mechanism ◽  
High Sensitivity ◽  
Fast Response ◽  
Polymeric Membrane ◽  
Selective Determination ◽  
Sensitivity And Selectivity ◽  
Pharmacologically Active

1-(3-chlorophenyl)piperazine (mCPP) is a wide spread new psychoactive substance produces stimulant and hallucinogenic effects similar to those sought from ecstasy. Hence, in the recent years, mCPP has been introduced by the organized crime through the darknet as a part of the illicit ecstasy market with a variable complex profile of pharmacologically active substances that pose problematic risk patterns among people who take these seized products. Accordingly, the design of selective sensors for the determination of mCPP is a very important demand. In this respect, a supramolecular architecture; [Na(15-crown-5)][BPh4] from the assembly of 15-crown-5 and sodium tetraphenylboron has been utilized as an ionophore, for the first time in the selective recognition of mCPP in conjunction with potassium tetrakis(p-chlorophenyl)borate and dioctylphthalate through polymeric membrane ion sensors. The ionophore exhibited a strong binding affinity that resulted in a high sensitivity with a slope closed to the ideal Nernstian value; 58.9 ± 0.43 mV/decade, a larger dynamic range from 10−6 to 10−2 M, a lower limit of detection down to 5.0 × 10−7 M and a fast response time of 5 s. Very important also is it was afforded excellent selectivity towards mCPP over psychoactive substances of major concern, providing a potentially useful system for the determination of mCPP in the illicit market. On comparison with the natural β-cyclodextrin as an ionophore, it exhibited more sensitivity and selectivity estimated to be the superior.

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