Journal articles: 'Voltammetry'

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Cemgil Sultan, Sinan, Esma Sezer, Yudum Tepeli, and Ulku Anik. "Centri-voltammetric dopamine detection." RSC Adv. 4, no. 59 (2014): 31489–92. http://dx.doi.org/10.1039/c4ra04887c.

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MENEK, Necati, Serpil ZEYREKLİ, and Yeliz KARAMAN. "Investigation of Electrochemical Behavior of Mordant Dye (C.I. 17135) at Glassy Carbon and Silver Electrodes." Chemia Naissensis 4, no. 1 (2021): 89–104. http://dx.doi.org/10.46793/chemn4.1.89m.

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In this study, the electrochemical behaviour of Mordant dye (C.I. 17135) was investigated in Britton-Robinson (BR) buffer (pH 2.0-12.0) media by using different voltammetric techniques: square wave voltammetry (SWV), cyclic voltammetry (CV), differential pulse voltammetry (DPV) and direct current voltammetry (DCV). The electrochemical behavior of the dye has been investigated by using a glassy carbon electrode (GCE) and silver electrode (SE). The brode peak of the azo dye occurred at SW and DP voltammograms, is due to its adsorption on the glassy carbon and silver electrode surfaces. Two reduction peaks were observed at pH < 9.5, and one reduction peak was observed at pH > 9.5 for SWV and DPV techniques at a glassy carbon electrode. From the voltammetric data electrochemical reaction mechanism of the azo dye has been suggested at glassy carbon and silver electrodes.

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Lu, Lin, Xianqiao Hu, and Zhiwei Zhu. "Joint Voltammetry Technology with a Multi-electrode Array for Four Basic Tastes." Current Analytical Chemistry 15, no. 1 (December 5, 2018): 75–83. http://dx.doi.org/10.2174/1573411014666180522100504.

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Background: Rapid and easy technology which can mimic the tongue for the simultaneous perception of several tastes based on sensory analysis and mathematical statistics is sorely needed. Methods: Joint voltammetry technology was developed to qualitatively and quantitatively analyze four basic tastes namely sweetness, saltiness, sourness and bitterness with the multi-electrode array. Four taste stimuli were corresponded to four tastes. Cyclic Voltammetry (CV), Differential Pulse Voltammetry (DPV) and Square Wave Voltammetry (SWV) were employed. The original voltammetric signals were transformed by Continuous Wavelet Transform (CWT) in order to reveal more feature information for sensing taste stimuli. Joint voltammetry was applied via the combination of voltammetry. The data of feature points from the transformed signal as the input were used for neural network model. Results: Layer-Recurrent neural network (LRNN) could effectively identify the types of stimuli. The accuracies of the training set and test set by joint voltammetry were both higher than that of regular voltammetry, confirming that Back Propagation neural network (BPNN) could quantitatively predict single taste stimulus of the mixture. Conclusion: Joint voltammetry technology had a strong ability to sense basic tastes as human tongue.

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Mirčeski, Valentin, Leon Stojanov, and Sławomira Skrzypek. "RECENT ADVANCES AND PROSPECTS OF SQUARE-WAVE VOLTAMMETRY." Contributions, Section of Natural, Mathematical and Biotechnical Sciences 39, no. 2 (December 28, 2018): 103. http://dx.doi.org/10.20903/csnmbs.masa.2018.39.2.123.

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This review concerns recent methodological advances of square-wave voltammetry as one of the most sophisticatedmembers of the pulse voltammetric techniques. Besides addressing recent theoretical works and representatives ofadvanced analytical studies, an emphasis is given to a few novel methodological concepts such as kinetic analysis atconstant scan rate, cyclic square-wave voltammetry, multisampling square-wave voltammetry, and electrochemical faradaicspectroscopy. For the purpose of improving analytical performances of the technique two new methods are proposedfor the first time.

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Shanmugam, Kumaran, Jiří Barek, and Jiří Zima. "Polarographic and Voltammetric Determination of Submicromolar Concentrations of Genotoxic 1,5-Dinitronaphthalene." Collection of Czechoslovak Chemical Communications 69, no. 11 (2004): 2021–35. http://dx.doi.org/10.1135/cccc20042021.

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Polarographic and voltammetric behavior of 1,5-dinitronaphthalene was investigated using tast polarography and differential pulse polarography at a classic dropping mercury electrode and differential pulse voltammetry and adsorptive stripping voltammetry at a hanging mercury drop electrode. Optimum conditions have been found for the determination of tested substance in the concentration range 2-10 μmol l-1 in tast polarography, 0.2-1 μmol l-1 in differential pulse polarography at a classic dropping mercury electrode or differential pulse voltammetry at a hanging mercury drop electrode, and 0.02-0.1 μmol l-1 using adsorptive stripping voltammetry. A possible mechanism of the electrochemical reduction of 1,5-dinitronaphthalene at mercury electrodes is discussed.

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Karastogianni, Sophia, and Stella Girousi. "Electrochemical Behavior and Voltammetric Determination of a Manganese(II) Complex at a Carbon Paste Electrode." Analytical Chemistry Insights 11 (January 2016): ACI.S32150. http://dx.doi.org/10.4137/aci.s32150.

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Investigation of the electrochemical behavior using cyclic voltammetry and detection of [Mn2+(thiophenyl-2-carboxylic acid)2 (triethanolamine)] with adsorptive stripping differential pulse voltammetry. The electrochemical behavior of a manganese(II) complex [Mn2+(thiophenyl-2-carboxylic acid)2(triethanolamine)] (A) was investigated using cyclic and differential pulse voltammetry in an acetate buffer of pH 4.6 at a carbon paste electrode. Further, an oxidation-reduction mechanism was proposed. Meanwhile, an adsorptive stripping differential pulse voltammetric method was developed for the determination of manganese(II) complex.

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Elqudaby, Hoda M., Hassan A. M. Hendawy, Eglal R. Souaya, Gehad G. Mohamed, and Ghada M. G. Eldin. "Utility of Activated Glassy Carbon and Pencil Graphite Electrodes for Voltammetric Determination of Nalbuphine Hydrochloride in Pharmaceutical and Biological Fluids." International Journal of Electrochemistry 2016 (2016): 1–9. http://dx.doi.org/10.1155/2016/8621234.

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This work compares voltammetric response of nalbuphine hydrochloride (NP·HCl) at both activated glassy carbon and pencil graphite electrodes. The electrochemical oxidation of the drug was studied using cyclic voltammetry (CV), differential pulse voltammetry (DPV), and square wave voltammetry (SWV) techniques. For analytical purpose a well-resolved irreversible diffusion controlled voltammetric peak was established in Britton-Robinson (B-R) buffer solution of pH 6.00 using pencil graphite electrode (PGE). Using activated glassy carbon electrode (GCE) a well-resolved irreversible diffusion controlled voltammetric peak was obtained at pH 7.00 using the same buffer solution. According to the linear relationship between the peak current and NP·HCl concentration, DPV and SWV methods were developed for their quantitative determination in pharmaceutical and human biological fluids. The linear response was obtained in the range from1.6×10-5to1.5×10-4 mol L−1using PGE and from12.5×10-6to13.75×10-5 mol L−1using a GC electrode, respectively. Precision and accuracy of the developed method were checked by recovery studies.

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Al-Owais, A. A., and I. S. El-Hallag. "Voltammetric Studies of Anthracen-9-ylmethylene-(3,4-dimethyl-isoxazol-5-yl)-amine Compound at Platinium Electrode." Journal of New Materials for Electrochemical Systems 18, no. 3 (September 9, 2015): 177–81. http://dx.doi.org/10.14447/jnmes.v18i3.366.

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The voltammetric behavior of anthracen-9-ylmethylene-(3,4-dimethyl-isoxazol-5-yl)-amine compound at Platinium electrode has been performed via convolutive cyclic voltammetry and digital simulation techniques using a conventional platinium electrode in 0.1 mol L-1 tetrabutylammonium perchlorate (TBAP) in acetonitrile solvent (CH3CN). The compound loss one electron forming radical cation followed by fast chemical step and the radical cation loss another two electrons producing trication which followed by chemical reaction (ECEC). Cyclic voltammetry and convolutive voltammetry were used for determination of the chemical and the electrochemical parameters of the electrode reaction pathway of the investigated compound. The Electrochemical parameters such as α, ks, Eo , D, and kc of the investigated isoxazol derivative were verified via digital simulation technique. Voltammetric studies of the investigated isoxazol derivative compound under consideration was presented and discussed.

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Inam, Onur, Ersin Demir, and Bengi Uslu. "Voltammetric Pathways for the Analysis of Ophthalmic Drugs." Current Pharmaceutical Analysis 16, no. 4 (April 27, 2020): 367–91. http://dx.doi.org/10.2174/1573412915666190225163637.

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Background: This review investigates the ophthalmic drugs that have been studied with voltammetry in the web of science database in the last 10 years. Introduction: Ophthalmic drugs are used in the diagnosis, evaluation and treatment of various ophthalmological diseases and conditions. A significant literature has emerged in recent years that investigates determination of these active compounds via electroanalytical methods, particularly voltammetry. Low cost, rapid determination, high availability, efficient sensitivity and simple application make voltammetry one of the most used methods for determining various kinds of drugs including ophthalmic ones. Methods: In this particular review, we searched the literature via the web of science database for ophthalmic drugs which are investigated with voltammetric techniques using the keywords of voltammetry, electrochemistry, determination and electroanalytical methods. Results: We found 33 types of pharmaceuticals in nearly 140 articles. We grouped them clinically into seven major groups as antibiotics, antivirals, non-steroidal anti-inflammatory drugs, anti-glaucomatous drugs, steroidal drugs, local anesthetics and miscellaneous. Voltammetric techniques, electrodes, optimum pHs, peak potentials, limit of detection values, limit of quantification values, linearity ranges, sample type and interference effects were compared. Conclusion: Ophthalmic drugs are widely used in the clinic and it is important to determine trace amounts of these species analytically. Voltammetry is a preferred method for its ease of use, high sensitivity, low cost, and high availability for the determination of ophthalmic drugs as well as many other medical drugs. The low limits of detection values indicate that voltammetry is quite sufficient for determining ophthalmic drugs in many media such as human serum, urine and ophthalmic eye drops.

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CHENG, CHING-CHING, MING-SHING YOUNG, SHANG-WEN YOUNG, and CHANG-LIN CHUANG. "AN INTELLIGENT DIGITAL VOLTAMMETRIC SYSTEM WITH MULTIPLE FUNCTIONS EXECUTED THROUGH STAND-ALONE OPERATION OR PC-CONTROL." Biomedical Engineering: Applications, Basis and Communications 14, no. 05 (October 25, 2002): 218–36. http://dx.doi.org/10.4015/s1016237202000322.

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This study presents an intelligent voltammetric system consisting of a personal computer and a digital voltammeter with VXIbus architecture of system control board, voltammetric measurement board and electrode evaluation board. System is designed to provide superior, comprehensive, versatile and convenient storage, analysis and display of electrochemical and voltammetric waveforms. Voltammeter is capable of stand-alone operation or direct PC control through a Labview program and serial communication interface. Stand-alone offers several general voltammetric functions such as electrochemical treatment and evaluation of electrodes and experimental voltammetry. PC connection gives additional functions such as automatic scanning of oxidation potential, expanded storage and processing of experimental data, arbitrary voltammetric waveform parameters, etc. Standalone uses microcontroller and three-bus structure, with EEPROM storing waveform parameters, experimental data and machine code program downloaded from PC. Electrode evaluation board tests electrode quality by measuring electrode equivalent resistance and capacitance, requiring only one button to perform the entire procedure. Minimum potential unit is 1 mV, at which setting the voltage range is −2.05 to +2.05 V. At a minimum unit of 4.9 mV, the voltage range is −10 to +10V. Experimental results are presented using carbon fiber electrode to measure the dopamine concentration in PBS solution, showing minimum oxidation current can be measured to less than 10 pA, with a minimum detectable bulk concentration of less than 10 ppb. The combination of PC with stand-alone voltammeter offers high-speed, precision, automation, versatility and portability, while the VXIbus architecture allows easy expansion capability.

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Shergill, Ricoveer Singh, Petra Kristova, and Bhavik Anil Patel. "Detection of falsified clopidogrel in the presence of excipients using voltammetry." Analytical Methods 13, no. 44 (2021): 5335–42. http://dx.doi.org/10.1039/d1ay01602d.

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Amro, Abdulaziz N. "Voltammetric Method Development for Itopride Assay in a Pharmaceutical Formulation." Current Pharmaceutical Analysis 16, no. 3 (March 31, 2020): 312–18. http://dx.doi.org/10.2174/1573412915666190912122421.

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Background: Itopride used for the gastrointestinal symptoms caused by reduced gastrointestinal mobility. For the first time rapid, low cost and green voltammetric method has been applied to analyze itopride in pharmaceutical formulation. Method: Cyclic Voltammetry (CV), Linear Sweep Voltammetry (LSV), Square Wave Voltammetry (SWV) and Differential Pulse Voltammetry (DPV) methods have been applied in this study. Results: Na2SO4 (1M) supporting electrolyte exhibited sharper anodic peak current than other used supporting electrolytes; glassy carbon electrode (GC) working electrode shows better results than platinum electrode (Pt). SWV results show the lowest limit of detection and quantitation values of 2.3 and 18.1 μg.mL-1, respectively. SWV recovery is 100.56% and 100.46% for 50 μg.mL-1 and 100 μg.mL-1 of commercially available itopride tablets, respectively. Furthermore, SWV inter and intraday results precessions are better than other used methods with 0.96 and 0.56% RSD, respectively. Conclusion: The optimum method of applied methods in this study is SWV method. Voltammetry showed low LOD and LOQ values with high accuracy and precession in addition to comparable repeatability and reproducibility values.

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Srivastava, Ashwini K., Sharad S. Upadhyay, Chaitali R. Rawool, Ninad S. Punde, and Anuja S. Rajpurohit. "Voltammetric Techniques for the Analysis of Drugs using Nanomaterials based Chemically Modified Electrodes." Current Analytical Chemistry 15, no. 3 (May 7, 2019): 249–76. http://dx.doi.org/10.2174/1573411014666180510152154.

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Background: Electroanalytical techniques play a very important role in the areas of medicinal, clinical as well as pharmaceutical research. Amongst these techniques, the voltammetric methods for the determination of drugs using nanomaterials based chemically modified electrodes (CMEs) have received enormous attention in recent years. This is due to the sensitivity and selectivity they provide on qualitative as well as quantitative aspects of the electroactive analyte under study. The aim of the present review was to discuss the work on nanomaterials based CMEs for the analysis of drugs covering the period from 2000 to present employing various voltammetric techniques for different classes of the drugs. Methods: The present review deals with the determination of different classes of drugs including analgesics, anthelmentic, anti-TB, cardiovascular, antipsychotics and anti-allergic, antibiotic and gastrointestinal drugs. Also, a special section is devoted for enantioanalysis of certain chiral drugs using voltammetry. The detailed information of the voltammetric determination for the drugs from each class employing various techniques such as differential pulse voltammetry, cyclic voltammetry, linear sweep voltammetry, square wave voltammetry, stripping voltammetry, etc. are presented in tabular form below the description of each class in the review. Results: Various nanomaterials including carbon nanotubes, graphene, carbon nanofibers, quantum dots, metal/metal oxide nanoparticles, polymer based nanocomposites have been used by researchers for the development of CMEs over a period of time. The large surface area to volume ratio, high conductivity, electrocatalytic activity and biocompatibility make them ideal modifiers where they produce synergistic effect which helps in trace level determination of pharmaceutical, biomedical and medicinal compounds. In addition, macrocyclic compounds as chiral selectors have been used for the determination of enantiomeric drugs where one of the isomers captured in the cavities of chiral selector shows stronger binding interaction for one of the enantiomorphs. Conclusion: arious kinds of functional nanocomposites have led to the manipulation of peak potential due to drug - nanoparticles interaction at the modified electrode surface. This has facilitated the simultaneous determination of drugs with almost similar peak potentials. Also, it leads to the enhancement in voltammetric response of the analytes. It is expected that such modified electrodes can be easily miniaturized and used as portable, wearable and user friendly devices. This will pave a way for in-vivo onsite real monitoring of single as well as multi component pharmaceutical compounds.

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Ghanem, Mohamed A., Ibrahim S. El-Hallag, and Abdullah M. Al-Mayouf. "Electrochemical Behavior and Convoluted Voltammetry of Carbon Nanotubes Modified with Anthraquinone." Journal of New Materials for Electrochemical Systems 20, no. 1 (April 23, 2017): 025–30. http://dx.doi.org/10.14447/jnmes.v20i1.291.

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The validity of convolution voltammetry for determination accurate values of diffusion coefficient (D) and electrons number (n) consumed in electrochemical reaction has been explained by applying the technique to a carbon nanotubes chemically modified using func-tional groups of anthraquinone(AQ). The analysis with macrodisk electrode was facilitated due to the presence of minor contribution of nonfaradaic current, so moderate values of sweep speed can be used without subtraction of residual current to quantify the diffusivity of electro-active species.The values of D and nCb were determined simultaneously and demonstrated using convoluted procedure. The ob-tained results indicate that the convolution voltammetry provides advantages over constant state methods (plateau) such as micro-disk electrode voltammetry and rotating disk electrode voltammetry, as it is not limited by the method of diffusion (planar or radial), which remove the limitations of solvent viscosity, geometry of electrode, and voltammetric sweep speed.

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Vercelli, Barbara, Sara Crotti, and Marco Agostini. "Voltammetric responses at modified electrodes and aggregation effects of two anticancer molecules: irinotecan and sunitinib." New Journal of Chemistry 44, no. 42 (2020): 18233–41. http://dx.doi.org/10.1039/d0nj03896b.

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Patil, Ketan, and Astha Pandey. "Voltammetric Analysis of New Psychoactive Substances." Arab Journal of Forensic Sciences and Forensic Medicine 3, no. 2 (December 30, 2021): 297–314. http://dx.doi.org/10.26735/mzyc3707.

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New Psychoactive Substances (NPS) are synthetic drugs that create similar effects as various narcotic drugs and psychotropic substances. Different NPS such as mephedrone, synthacaine, synthetic cannabinoids, etc. are available today which are sold across numerous platforms like drug markets, head shops, the dark web, etc. They are emerging rapidly and becoming popular in society because of their variable nature and ease in avoiding breaking the law. Consequently, their analysis is extremely crucial in the prohibition of drug abuse and the development of laboratory methods. This review introduces a broad overview of the analysis of various new psychoactive substances by voltammetric techniques such as cyclic voltammetry, differential pulse voltammetry, square wave voltammetry, stripping voltammetry etc. It also focuses on various methodologies that were developed for the detection of these NPS which play a leading role in forensic investigation by providing a rapid, sensitive, and cost-effective platform of analysis. The need for the advancement of various detection methods and analysis of more drugs is additionally discussed.

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Senda, Mitsugi, Hajime Katano, and Yuko Kubota. "Stripping Analysis Using Ion-Transfer Voltammetry at Liquid/Liquid Interface." Collection of Czechoslovak Chemical Communications 66, no. 3 (2001): 445–55. http://dx.doi.org/10.1135/cccc20010445.

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Principles and theory of stripping ion-transfer voltammetry at the organic solvent (O)/water (W) interface are described, in which a thin O-film is used to preconcentrate an ionic substance by electroextraction followed by stripping analysis using linear sweep voltammetry or normal pulse voltammetry. For ease of handling, the thin O-film was gelled by adding poly(vinyl chloride) to make an O-gel electrode. Lead(II), cadmium(II) and zinc(II) ions behave reversibly or quasi-reversibly in voltammetric transfer at the O/W interface assisted by 5,6-diphenyl-3-(2-pyridyl)-1,2,4-triazine (DPT) present in the O-phase. Thus, these ions at trace levels can be determined using stripping ion-transfer voltammetry with the O(DPT)-gel electrode. The detection limit was as low as a few tens of nmol/l of these ions. Simultaneous determination of two or more ions is possible when their half-wave potentials of ion transfer are reasonably separated.

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Tur'yan, Y. "Microcells for voltammetry and stripping voltammetry." Talanta 44, no. 1 (January 1997): 1–13. http://dx.doi.org/10.1016/s0039-9140(96)02040-1.

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Ağın, Fatma. "Voltammetric Determination of Guaifenesin in Pharmaceuticals and Urine Samples Based on Poly(Bromocresol Purple) Modified Glassy Carbon Electrode." Current Pharmaceutical Analysis 16, no. 5 (June 15, 2020): 633–39. http://dx.doi.org/10.2174/1573412915666190114154434.

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Introduction: The electro-oxidation behavior of expectorant drug Guaifenesin (GUF) was studied on poly(bromocresol purple) modified Glassy Carbon Electrode (GCE) by Cyclic Voltammetry (CV) and Differential Pulse Voltammetry (DPV) methods. Materials and Methods: GCE was modified with electropolymerization of Bromocresol Purple (BP) monomer for sensitive determination of GUF with voltammetric methods. The oxidation process of GUF showed irreversible and diffusion controlled behavior. The linearity has been obtained in the range from 1.00 × 10-7 to 2.00 × 10-5 M with the limit of detection 3.658 × 10-9 M for DPV in 0.1 M phosphate buffer solution (PBS) at pH 3.0. Results and Conclusion: Fully validated differential pulse voltammetry was successfully applied for the determination of GUF in pharmaceutical dosage forms and urine samples obtained satisfying results.

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Şahin, Nuriye, and Mutlu Sönmez Çelebi. "Electrocatalytic Oxidation of Ethanol and Bioethanol Using Poly(thionine) Supported Platinum Nano/Micro Particles." Ordu Üniversitesi Bilim ve Teknoloji Dergisi 14, no. 1 (June 30, 2024): 141–53. http://dx.doi.org/10.54370/ordubtd.1430775.

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Pt micro/nano particles were supported on poly(thionine) conducting polymer and used as catalyst for electrochemical oxidation of ethanol. Thionine was polymerized from its aqueous solution by cyclic voltammetry. Incorporation of Pt complex was carried out electrochemically by polycyclic voltammetry using K2PtCl4 as the precursor prior to reduction. Evaluation of optimum experimental parameters was done according to the obtained oxidation currents recorded in ethanol solutions with cyclic voltammetry. For the physical characterization of the Pt/PTH catalyst prepared under optimum conditions, SEM images were recorded. When the cyclic voltammetric behavior of bioethanol with the Pt/PTH catalyst prepared under optimum conditions was examined and compared with synthetic ethanol, it was revealed that the developed catalyst showed high catalytic activity for bioethanol oxidation.

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Grabarczyk, Malgorzata, and Marzena Adamczyk. "Bismuth film electrode and chloranilic acid as a new alternative for simple, fast and sensitive Ge(iv) quantification by adsorptive stripping voltammetry." RSC Advances 8, no. 27 (2018): 15215–21. http://dx.doi.org/10.1039/c8ra01160e.

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Areias, Madalena C. C., Kenichi Shimizu, and Richard G. Compton. "Voltammetric detection of glutathione: an adsorptive stripping voltammetry approach." Analyst 141, no. 10 (2016): 2904–10. http://dx.doi.org/10.1039/c6an00550k.

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Ibrahim, Mohamed S., Zahra A. Ahmed, Moustafa M. Kamal, and Yassein M. Temerk. "Adsorption and Accumulation of Neutral Red at Mercury/Solution Interface." Collection of Czechoslovak Chemical Communications 60, no. 1 (1995): 65–75. http://dx.doi.org/10.1135/cccc19950065.

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The voltammetric behaviour of protonated and nonprotonated neutral red (NR) has been studied at a hanging mercury drop electrode (HMDE) by using alternating current (AC) and cyclic voltammetry (CV). The AC voltammetric behaviour and the morphology of the adsorption redox peaks indicate that interactions between adsorbed molecules are substantial and that the nature of these interactions changes from moderately repulsive below pH 4 to strongly attractive above pH 6. Controlled adsorptive accumulation of NR on the HMDE provides the basis for the direct stripping measurement of that compound in the nanomolar concentration level. Adsorptive phase selective AC stripping voltammetry has been proved to be advantageous over any other assay technique, allowing a detection limit of 1.0 . 10-9 M NR to be reached.

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Yonekura, Tatsuya, Takeo Ohsaka, Fusao Kitamura, and Koichi Tokuda. "Synthesis and electrochemical properties of bis(octacyanophthalocyaninato)neodymium(III) complex." Journal of Porphyrins and Phthalocyanines 09, no. 01 (January 2005): 54–58. http://dx.doi.org/10.1142/s1088424605000101.

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The bis(octacyanophthalocyaninato)neodymium(III) was synthesized and its electrochemical behavior in N,N-dimethylformamide ( DMF ) was investigated by cyclic voltammetry (CV) and square wave voltammetry (SWV). Multiple redox reactions were observed on the cyclic voltammogram, although the voltammetric feature was complicated due to aggregation. With the aid of SWV, it was concluded that the redox potentials of the complex positively shifted by about 700 mV compared with potentials of the unsubstituted complex, which was ascribed to the strong electron-withdrawn effect of the substituted cyano group.

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Inaudi, Paolo, Ornella Abollino, Monica Argenziano, Mery Malandrino, Caterina Guiot, Stefano Bertinetti, Laura Favilli, and Agnese Giacomino. "Advancements in Portable Voltammetry: A Promising Approach for Iron Speciation Analysis." Molecules 28, no. 21 (November 3, 2023): 7404. http://dx.doi.org/10.3390/molecules28217404.

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Iron, a crucial element in our environment, plays a vital role in numerous natural processes. Understanding the presence and concentration of iron in the environment is very important as it impacts various aspects of our planet’s health. The on-site detection and speciation of iron are significant for several reasons. In this context, the present work aims to evaluate the applicability of voltammetry for the on-site determination of iron and its possible speciation using a portable voltammetric analyzer. Voltammetry offers the advantage of convenience and cost-effectiveness. For iron (III) determination, the modification of a glassy carbon electrode (GCE) with an antimony-bismuth film (SbBiFE) using the acetate buffer (pH = 4) as a supporting electrolyte was used. The technique adopted was Square Wave Adsoptive Cathodic Stripping Voltammetry (SW-AdCSV), and we used 1-(2-piridylazo)-2-naphthol (PAN) as the iron (III) ligand. Linearity, repeatability, detection limit, and accuracy were determined using synthetic solutions; then, a Standard Reference Material (SRM) of 1643f Trace Elements in Water (iron content: 93.44 ± 0.78 µg L−1) was used for validation measurements in the real matrix. the accuracy of this technique was found to be excellent since we obtained a recovery of 103.16%. The procedure was finally applied to real samples (tap, lake, and seawater), and the results obtained were compared via Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES). The amount of iron found was 207.8 ± 6.6 µg L−1 for tap water using voltammetry and 200.9 ± 1.5 µg L−1 with ICP-OES. For lake water, 171.7 ± 3.8 µg L−1, 169.8 ± 4.1 µg L−1, and 187.5 ± 5.7 µg L−1 were found using voltammetry in the lab both on-site and using ICP-OES, respectively. The results obtained demonstrate the excellent applicability of the proposed on-site voltammetric procedure for the determination of iron and its speciation in water.

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Anik, Ulku, and Serdar Çevik. "Centri-voltammetry for biosensing systems: biocentri-voltammetric xanthine detection." Microchimica Acta 174, no. 3-4 (May 20, 2011): 207–12. http://dx.doi.org/10.1007/s00604-011-0615-2.

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Phong, Nguyen Hai, Tran Thanh Tam Toan, Mai Xuan Tinh, Tran Ngoc Tuyen, Tran Xuan Mau, and Dinh Quang Khieu. "Simultaneous Voltammetric Determination of Ascorbic Acid, Paracetamol, and Caffeine Using Electrochemically Reduced Graphene-Oxide-Modified Electrode." Journal of Nanomaterials 2018 (August 27, 2018): 1–15. http://dx.doi.org/10.1155/2018/5348016.

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In the present paper, graphene oxide was directly electrodeposited by means of cyclic voltammetric techniques on the glassy-carbon electrode (GCE) to obtain a reduced graphene-oxide-modified electrode (ErGO/GCE). Cyclic voltammetry (CV) and differential pulse anodic stripping voltammetry (DP-ASV) had been utilized to study the electrochemical behavior of ErGO/GCE toward ascorbic acid (AA), paracetamol (PA), and caffeine (CA). Differential pulse voltammetry results show that AA, PA, and CA could be detected selectively and sensitively on ErGO/GCE with peak-to-peak separation of 312 mV and 756 mV for AA–PA and PA–CA, respectively. The factors affecting the voltammetric signals such as pH, scan rate, and interferents were addressed. The results reveal that the ErGO/GCE-modified electrode exhibits excellent electrochemical activity in the oxidation of PA, CA, and AA. The detection limits are 0.36 μM, 0.25 μM, and 0.23 μM for AA, PA and CA, respectively, suggesting that the ErGO/GCE can be utilized with high sensitivity and selectivity for the simultaneous determination of these compounds. Finally, the proposed method was successfully used to determine AA, PA, and CA in pharmaceutical preparations.

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Chihava, Ruvimbo, Daniel Apath, Mambo Moyo, Munyaradzi Shumba, Vitalis Chitsa, and Piwai Tshuma. "One-Pot Synthesized Nickel-Cobalt Sulfide-Decorated Graphene Quantum Dot Composite for Simultaneous Electrochemical Determination of Antiretroviral Drugs: Lamivudine and Tenofovir Disoproxil Fumarate." Journal of Sensors 2020 (July 2, 2020): 1–13. http://dx.doi.org/10.1155/2020/3124102.

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In the present study, simultaneous electrochemical behavior of tenofovir disoproxil fumarate (TDF) and lamivudine (LAM) on a glassy carbon electrode (GCE) modified with a novel nanocomposite, nickel-cobalt sulfide-decorated graphene quantum dots (Ni-CoS/GQDs) was investigated. Characterization of different components used for modifications was achieved using UV-Vis and transmission electron microscopy (TEM). The electrochemistry of TDF and LAM at the modified electrode was examined using cyclic voltammetry (CV), linear sweep voltammetry (LSV), chronoamperometry, differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS). A substantial (+39 mV TDF; +20 mV LAM) decrease in potential on oxidation reaction in 0.1 M PBS (pH 8.0) was achieved due to synergy between Ni-CoS and GQDs. Using optimized voltammetric parameters and pH, DPV gave a linear calibration over the range 5-18 μM for TDF and LAM. The detection limits were calculated as 2.42×10−8 mM (LAM) and 1.21×10−8 mM (TDF). The estimated values for Gibbs free energy revealed adsorption of TDF and LAM on Ni-CoS/GQDs/GCE as a spontaneous and favorable process. The voltammetric method was applied for determination of LAM and TDF in a pharmaceutical formulation giving average recovery of 99.65%.

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Nissim, Rita, and Richard G. Compton. "Introducing absorptive stripping voltammetry: wide concentration range voltammetric phenol detection." Analyst 139, no. 22 (2014): 5911–18. http://dx.doi.org/10.1039/c4an01417k.

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Babar, Dipak Gorakh, Nidhi Rani Gupta, Goutam Nandi, and Sabyasachi Sarkar. "Carbon Nano Onions–Polystyrene Composite for Sensing S-Containing Amino Acids." Journal of Composites Science 4, no. 3 (July 10, 2020): 90. http://dx.doi.org/10.3390/jcs4030090.

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A carbon nano-onions (CNOs)–polystyrene (PS) composite-based Pt electrode was used for the voltammetric detection of cysteine (Cys) and methionine (Met). The electrochemical behaviors of Cys and Met were analyzed with Cyclic Voltammetry (CV) and Differential Pulse (DP) Voltammetry at different pHs. The modified CNOs–PS/Pt electrode shows an oxidation peak at +0.4V for Cys and +0.8V for Met, respectively. Admirable sensitivity, easy fabrication, and reproducible performance make the proposed electrode well functional and useful for the qualitative and quantitative detection of sulphur-containing amino acids.

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31

Anik, Ülkü. "Centri-voltammetry and biocentri-voltammetry: a review." Microchimica Acta 180, no. 9-10 (April 17, 2013): 741–49. http://dx.doi.org/10.1007/s00604-013-0986-7.

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Wang, Hsiang-Wei, Cameron Bringans, Anthony J. R. Hickey, John A. Windsor, Paul A. Kilmartin, and Anthony R. J. Phillips. "Cyclic Voltammetry in Biological Samples: A Systematic Review of Methods and Techniques Applicable to Clinical Settings." Signals 2, no. 1 (March 16, 2021): 138–58. http://dx.doi.org/10.3390/signals2010012.

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Oxidative stress plays a pivotal role in the pathogenesis of many diseases, but there is no accurate measurement of oxidative stress or antioxidants that has utility in the clinical setting. Cyclic Voltammetry is an electrochemical technique that has been widely used for analyzing redox status in industrial and research settings. It has also recently been applied to assess the antioxidant status of in vivo biological samples. This systematic review identified 38 studies that used cyclic voltammetry to determine the change in antioxidant status in humans and animals. It focusses on the methods for sample preparation, processing and storage, experimental setup and techniques used to identify the antioxidants responsible for the voltammetric peaks. The aim is to provide key information to those intending to use cyclic voltammetry to measure antioxidants in biological samples in a clinical setting.

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33

Cao, Yu, Zhihui Fang, Duanguang Yang, Yong Gao, and Huaming Li. "Voltammetric Sensor for Sudan I Based on Glassy Carbon Electrode Modified by SWCNT/β-Cyclodextrin Conjugate." Nano 10, no. 02 (February 2015): 1550026. http://dx.doi.org/10.1142/s1793292015500265.

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We reported a sensitive voltammetric sensor for Sudan I determination by modifying glassy carbon electrode (GCE) with single-walled carbon nanotubes (SWCNTs)/β-cyclodextrin conjugate. The cyclic voltammetry results showed that the modified GCE exhibited strong catalytic activity toward the electro-reduction of Sudan I with a well-defined cyclic voltammetric peak at -673 mV. Differential pulse voltammetry measurement showed that the response current exhibited a linear range between 50 nM and 5 μM, and the detection limit was as low as 2.22 nM (S/N = 3). The enhanced electrochemical performance of the fabricated sensor was attributed to the combination of the excellent electrocatalytic properties of SWCNTs and the molecular recognition ability of β-cyclodextrin to Sudan I. The sensor was successfully applied to determine Sudan I in real food samples with satisfactory results.

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34

Vilas-Boas, Ângela, Patrícia Valderrama, Natacha Fontes, Dulce Geraldo, and Fátima Bento. "Evaluation of total polyphenol content of wines by means of voltammetric techniques: Cyclic voltammetry vs differential pulse voltammetry." Food Chemistry 276 (March 2019): 719–25. http://dx.doi.org/10.1016/j.foodchem.2018.10.078.

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35

Vo, Nguyen T., Alan M. Bond, and Lisandra L. Martin. "Electrochemically Directed Synthesis of Cobalt(II) and Nickel(II) TCNQF21–/2– Coordination Polymers: Solubility and Substituent Effects in the TCNQFn (n=0, 1, 2, 4) Series of Complexes." Australian Journal of Chemistry 73, no. 12 (2020): 1197. http://dx.doi.org/10.1071/ch20187.

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The reversible diffusion controlled cyclic voltammetry for the reduction of TCNQFn0/1–/2– (where n=0, 1, 2, 4) changes significantly on addition of Co2+ and Ni2+ transition metal ions (M2+) because the kinetics associated with electrocrystallisation of the resulting coordination polymers [M(TCNQF2)2(H2O)2] and [M(TCNQF2)] are rapid on the voltammetric time scale. The voltammetry of solutions containing M2+ and TCNQF2 was undertaken in acetonitrile (0.1M Bu4NPF6) at both GC and ITO electrodes. New one electron reduced TCNQF2 materials prepared via electrochemically directed synthesis were shown to have the formula [M(TCNQF2)2(H2O)2], assessed by vibrational (IR and Raman) spectroscopy, elemental analysis and thermogravimetric analysis. The solubility of [Ni(TCNQF2)2(H2O)2] (Ksp=8.29×10−11 M3) was significantly higher than the [Co(TCNQF2)2(H2O)2] (Ksp=1.43×10−11M3). Cyclic voltammetric data suggest the electrocrystallisation of two phases of [Ni(TCNQF2)2(H2O)2] occurs, which is not evident for [Co(TCNQF2)2(H2O)2]. Electrocrystallisation of the highly insoluble [M(TCNQF2)] was achieved at low M2+ and TCNQF2 concentrations. A comparison with published data on the voltammetry of TCNQFn (n=0, 1, 2 and 4) for the series of TCNQFn (n=0, 1, 2 and 4) containing M2+ is provided. An assessment of the electronic impact of the fluorine substituent of the underlying redox reactions also is established. Predictions are made for the voltammetric behaviour expected for the other transition metal cations with reduced TCNQFn derivatives.

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German, Natalija, Saulius Armalis, Jiří Zima, and Jiří Barek. "Voltammetric Determination of Fluoren-9-ol and 2-Acetamidofluorene Using Carbon Paste Electrodes." Collection of Czechoslovak Chemical Communications 70, no. 3 (2005): 292–304. http://dx.doi.org/10.1135/cccc20050292.

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Square wave voltammetry and differential pulse voltammetry have been used for the determination of 2-acetamidofluorene and fluoren-9-ol using carbon paste electrodes, following the study of the influence of the carbon paste composition on the voltammetric signals of the analytes. The methods are based on the oxidation of the above compounds and they include adsorptive accumulation of the analyte on the surface of the working electrode. The limit of detection was 1 μmol l-1for fluoren-9-ol in a medium of 0.1 M H2SO4, and 40 nmol l-1for 2-acetamidofluorene in Britton-Robinson buffer (pH 7).

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Gulaboski, Rubin, and Valentin Mirceski. "Surface catalytic mechanism-theoretical study under conditions of differential square-wave voltammetry." Macedonian Journal of Chemistry and Chemical Engineering 41, no. 1 (June 30, 2022): 1–10. http://dx.doi.org/10.20450/mjcce.2022.2404.

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Differential square-wave voltammetry (DSWV) is the most recent modification of square-wave voltammetry (SWV) developed for advancing the performances of the technique for both analytical and kinetics applications. The differential current-measuring protocol in DSWV leads to improved voltammetric features of the forward and backward current components, in particular when slow i.e., quasireversible or irreversible electrode reactions are studied. In the present theoretical work catalytic electrode mechanism of surface bounded redox species (surface EC’ mechanism) is studied under conditions of the new technique, where E denotes the electrode reaction and C’ refers to the irreversible follow-up regenerative chemical reaction. Presented theoretical data provides a general overview of the EC’ reaction scheme, implying some specific voltammetric features which can be exploited for estimation of relevant physical parameters of the electrode reaction E and the regenerative chemical reaction C’.

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38

Gulaboski, Rubin, and Valentin Mirceski. "Application of voltammetry in biomedicine - Recent achievements in enzymatic voltammetry." Macedonian Journal of Chemistry and Chemical Engineering 39, no. 2 (November 12, 2020): 153. http://dx.doi.org/10.20450/mjcce.2020.2152.

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Protein-film voltammetry (PFV) is considered the simplest methodology to study the electrochemistry of lipophilic redox enzymes in an aqueous environment. By anchoring particular redox enzymes on the working electrode surface, it is possible to get an insight into the mechanism of enzyme action. The PFV methodology enables access to the relevant thermodynamic and kinetic parameters of the enzyme-electrode reaction and enzyme-substrate interactions, which is important to better understand many metabolic pathways in living systems and to delineate the physiological role of enzymes. PFV additionally provides important information which is useful for designing specific biosensors, simple medical devices and bio-fuel cells. In the current review, we focus on some recent achievements of PFV, while presenting some novel protocols that contribute to a better communication between redox enzymes and the working electrode. Insights to several new theoretical models that provide a simple strategy for studying electrode reactions of immobilized enzymes and that enable both kinetic and thermodynamic characterization of enzyme-substrate interactions are also provided. In addition, we give a short overview to several novel voltammetric techniques, derived from the perspective of square-wave voltammetry, which seem to be promising tools for application in PFV.

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39

Lazar, Ioana Georgiana, Elena Diacu, George Octavian Buica, Eleonora Mihaela Ungureanu, Georgiana Luiza Arnold, and Liviu Birzan. "The Heavy Metals Sensing Based on 2,6-Bis(-2-(Thiophen-3-yl)Vinyl)-4-(4,6,8-Trimethylazulen-1-yl)Pyrylium Modified Electrodes." Revista de Chimie 68, no. 11 (December 15, 2017): 2509–13. http://dx.doi.org/10.37358/rc.17.11.5917.

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This paper focuses on electrochemical characterization of new azulene compound 2,6-bis((E)-2-(thiophen-3-yl)vinyl)-4-(4,6,8-trimethylazulen-1-yl)pyrylium (L) by cyclic voltammetry (CV), differential pulse voltammetry (DPV), rotating disk electrode voltammetry (RDE) on glassy carbon disk working electrodes. The character of redox processes was established by CV and RDE using increasing scan rates at different scan domains. PolyL modified electrodes have been prepared by scanning or controlled potential electrolysis (CPE). The complexing properties of L and polyL have been investigated towards detection of heavy metal ions by anodic stripping technique. The voltammetric curves present well defined peaks for Pb2+, Cd2+, Cu2+ and Hg2+, which can be used as analytical signals for their determination. The performances of the modified electrodes obtained at different potentials and charges have been evaluated. The best results have been obtained for Pb2+ and Cd2+ with the achievement of detection limits of 10-7 M.

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40

Tajik, Somayeh, Fatemeh Sharifi, Behnaz Aflatoonian, and Antonio Di Bartolomeo. "A New Electrochemical Sensor for the Detection of Ketoconazole Using Carbon Paste Electrode Modified with Sheaf-like Ce-BTC MOF Nanostructure and Ionic Liquid." Nanomaterials 13, no. 3 (January 28, 2023): 523. http://dx.doi.org/10.3390/nano13030523.

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An ultrasensitive and selective voltammetric sensor with an ultratrace-level detection limit is introduced for ketoconazole (KTC) determination in real samples using a modified carbon paste electrode with a sheaf-like Ce-BTC MOF nanostructure and ionic liquid. The as-synthesized nanostructure was characterized by several techniques, including energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and field emission scanning electron microscopy (FE-SEM). The electrocatalytic performance of the developed electrode was observed by cyclic voltammetry (CV), differential pulse voltammetry (DPV), linear sweep voltammetry (LSV), and chronoamperometry. The limit of detection (LOD) of the developed sensor for KTC is 0.04 μM, and the response was found to be in the dynamic concentration range of 0.1–110.0 μM in a phosphate buffer solution. The proposed electrode exhibits acceptable electrocatalytic activity for KTC oxidation with a high sensitivity of 0.1342 μA·μM−1. The ability of the fabricated sensor to monitor KTC in real aqueous samples is demonstrated using standard addition data.

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41

Brazill, Sara A., Sharin E. Bender, Nicole E. Hebert, John K. Cullison, Eric W. Kristensen, and Werner G. Kuhr. "Sinusoidal voltammetry:." Journal of Electroanalytical Chemistry 531, no. 2 (August 2002): 119–32. http://dx.doi.org/10.1016/s0022-0728(02)01067-7.

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42

Bard, Allen J., and Cynthia G. Zoski. "Voltammetry Retrospective." Analytical Chemistry 72, no. 9 (May 2000): 346 A—352 A. http://dx.doi.org/10.1021/ac002791t.

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43

Brainina, Kh, and A. M. Bond. "Analytical voltammetry." TrAC Trends in Analytical Chemistry 12, no. 6 (June 1993): xiii—xiv. http://dx.doi.org/10.1016/0165-9936(93)87068-9.

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44

Smyth, MalcolmR. "Cyclic voltammetry." TrAC Trends in Analytical Chemistry 13, no. 8 (September 1994): 341. http://dx.doi.org/10.1016/0165-9936(94)87010-1.

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45

Speiser, Bernd. "Cyclic voltammetry." Journal of Electroanalytical Chemistry 374, no. 1-2 (August 1994): 280–82. http://dx.doi.org/10.1016/0022-0728(94)87045-4.

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46

Osteryoung, J. "Analytical voltammetry." Electrochimica Acta 38, no. 11 (August 1993): 1597. http://dx.doi.org/10.1016/0013-4686(93)80295-b.

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van den Berg, C. M. G. "Analytical Voltammetry." Analytica Chimica Acta 272, no. 2 (February 1993): 348. http://dx.doi.org/10.1016/0003-2670(93)80592-9.

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Rueda, M., E. Roldán, D. González-Arjona, and M. Sánchez. "Cyclic voltammetry and differential pulse voltammetry of rescinnamine." Journal of Electroanalytical Chemistry and Interfacial Electrochemistry 208, no. 1 (August 1986): 127–36. http://dx.doi.org/10.1016/0022-0728(86)90301-3.

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49

Ban, Zhiyong, Enno Kätelhön, and Richard G. Compton. "Voltammetry of porous layers: Staircase vs analog voltammetry." Journal of Electroanalytical Chemistry 776 (September 2016): 25–33. http://dx.doi.org/10.1016/j.jelechem.2016.06.003.

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Dong, Shaojun, and Jun He. "DECONVOLUTION VOLTAMMETRY AND AC VOLTAMMETRY AT DISK MICROELECTRODE." Chinese Journal of Applied Chemistry 5, no. 5 (October 1, 1988): 63–66. http://dx.doi.org/10.3724/j.issn.1000-0518.1988.5.63.

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Journal articles on the topic 'Voltammetry'

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