Effect of the substituent of the cation of N-octylpyridinium hexafluorophosphate in the electrical and electrochemical response of carbon paste electrodes modified with these ionic liquids

In this work, we studied carbon paste electrodes (CPEs) with two kinds of binders: mineral oil or ionic liquids (IL) derived from N-substituted octyl pyridinium bis(trifluoromethylsulfonyl)imide with the substituents H-, CH3-, CN- and CF3-. The work aims to study this series of IL and determine a possible effect of the substituent of the cation in the behavior of the IL as a binder of graphite for obtaining IL-CPEs. The electrochemical response and the electrical behavior were measured by cyclic voltammetry and electrochemical impedance spectroscopy, respectively. Surprisingly, the substituent does not affect the cyclic voltammetry response because in all the cases, high resistance and high capacitive currents were obtained. The best response in terms of conductivity is obtained by CPE. In the case of impedance measurements, the substituent does not cause differences, and in all the cases, the IL-CPEs show nearly the same responses. CPE shows lower capacitance and higher resistance for diffusion compared to the IL-CPEs due to his lower porosity. The high resistance showed by the IL-CPEs by cyclic voltammetry can be attributed to poorly intermolecular forces among graphite, water, electrolyte, and ILs as demonstrated by theoretical calculations.

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An Evaluation on Determining Dopamine and Uric Acid in the Presence Ascorbic Acid Aded Using Carbon Paste Electrodes Modified by Nanoclay-Ionic Liquids

Russian Journal of Electrochemistry ◽

10.1134/s102319352012006x ◽

2021 ◽

Vol 57 (7) ◽

pp. 757-764

Author(s):

E. Eslami ◽

Z. Pourghobadi

Keyword(s):

Ascorbic Acid ◽

Uric Acid ◽

Ionic Liquids ◽

Carbon Paste ◽

Carbon Paste Electrodes

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Imidazolium-based ionic liquids as modifiers of carbon paste electrodes for trace-level voltammetric determination of dopamine in pharmaceutical preparations

Journal of Molecular Liquids ◽

10.1016/j.molliq.2020.112900 ◽

2020 ◽

Vol 306 ◽

pp. 112900

Author(s):

Sanja Šekuljica ◽

Valéria Guzsvány ◽

Jasmina Anojčić ◽

Tímea Hegedűs ◽

Momir Mikov ◽

...

Keyword(s):

Ionic Liquids ◽

Pharmaceutical Preparations ◽

Voltammetric Determination ◽

Carbon Paste ◽

Trace Level ◽

Carbon Paste Electrodes

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Properties and recent advantages in N,Nʹ-dialkylimidazolium-ion liquids application in electrochemistry

Current Analytical Chemistry ◽

10.2174/1573411016999201022141930 ◽

2020 ◽

Vol 16 ◽

Author(s):

Marzieh Alizadeh ◽

Marzieh Nodehi ◽

Sadegh Salmanpour ◽

Fatemeh Karimi ◽

Afsaneh L. Sanati ◽

...

Keyword(s):

Ionic Liquid ◽

Ionic Liquids ◽

Room Temperature ◽

Electrochemical Sensors ◽

Review Paper ◽

Modified Electrodes ◽

Carbon Paste ◽

Imidazolium Ionic Liquid ◽

Carbon Paste Electrodes ◽

Wide Range

: N,Nʹ-dialkylimidazolium-ion liquids is one of the important ionic liquids with a wide range of application as conductive electrolyte and in electrochemistry. The modified electrodes create a new view in fabrication of electroanalytical sensors. Many modifiers have beeen suggested for modification of electroanalytical sensor since many years ago. Over these years, ionic liquids and especially room temperature ionic liquids have attracted more attention due to their wide range of electrochemical windows and high electrical conductivity. N,Nʹ-dialkylimidazolium-ion liquids are one of the main important ionic liquids suggested for modification of bare electrodes and especially carbon paste electrodes. Although many review articles have reported onthe use of ionic liquids in electrochemical sensors, no review article has been specifically introduced so far on the review of the advantages of N,Nʹ-dialkylimidazolium ionic liquid. Therefore, in this review paper we focused on the introduction of recent advantages of N,Nʹ-dialkyl imidazolium ionic liquid in electrochemistry.

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Influence of Nitrogen-Doped Carbon Dot and Silver Nanoparticle Modified Carbon Paste Electrodes on the Potentiometric Determination of Tobramycin Sulfate: A Comparative Study

Chemosensors ◽

10.3390/chemosensors9030052 ◽

2021 ◽

Vol 9 (3) ◽

pp. 52

Author(s):

Nermine V. Fares ◽

Passant M. Medhat ◽

Christine M. El Maraghy ◽

Sherif Okeil ◽

Miriam F. Ayad

Keyword(s):

Silver Nanoparticle ◽

Carbon Nanodots ◽

Carbon Paste ◽

X Ray Diffraction ◽

Loteprednol Etabonate ◽

Carbon Paste Electrodes ◽

Transmission Electron ◽

Nernstian Slope ◽

Nitrogen Doped Carbon ◽

Modified Carbon Paste Electrodes

Two inexpensive and simple methods for synthesis of carbon nanodots were applied and compared to each other, namely a hydrothermal and microwave-assisted method. The synthesized carbon nanodots were characterized using transmission electron microscopy (TEM), ultraviolet-visible (UV-Vis), photoluminescence (PL), Fourier transform-infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The synthesized microwave carbon nanodots had smaller particle size and were thus chosen for better electrochemical performance. Therefore, they were used for our modification process. The proposed electrodes performance characteristics were evaluated according to the IUPAC guidelines, showing linear response in the concentration range 10−6–10−2, 10−7–10−2, and 10−8–10−2 M of tobramycin with a Nernstian slope of 52.60, 58.34, and 57.32 mV/decade for the bare, silver nanoparticle and carbon nanodots modified carbon paste electrodes, respectively. This developed potentiometric method was used for quantification of tobramycin in its co-formulated dosage form and spiked human plasma with good recovery percentages and without interference of the co-formulated drug loteprednol etabonate and excipients.

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Polyvinyl Chloride Modified Carbon Paste Electrodes for Sensitive Determination of Levofloxacin Drug in Serum, Urine, and Pharmaceutical Formulations

Sensors ◽

10.3390/s21093150 ◽

2021 ◽

Vol 21 (9) ◽

pp. 3150

Author(s):

Fatehy M. Abdel-Haleem ◽

Sonia Mahmoud ◽

Nour Eldin T. Abdel-Ghani ◽

Rasha Mohamed El Nashar ◽

Mikhael Bechelany ◽

...

Keyword(s):

Bacterial Infections ◽

Pharmaceutical Preparation ◽

Pharmaceutical Formulations ◽

Selectivity Coefficient ◽

Pvc Membrane ◽

Carbon Paste ◽

Serum Samples ◽

Carbon Paste Electrodes ◽

Antibiotic Drug

Levofloxacin (LF) is a medically important antibiotic drug that is used to treat a variety of bacterial infections. In this study, three highly sensitive and selective carbon paste electrodes (CPEs) were fabricated for potentiometric determination of the LF drug: (i) CPEs filled with carbon paste (referred to as CPE); (ii) CPE coated (drop-casted) with ion-selective PVC membrane (referred to as C-CPE); (iii) CPE filled with carbon paste modified with a plasticizer (PVC/cyclohexanone) (referenced as P-CPE). The CPE was formulated from graphite (Gr, 44.0%) and reduced graphene oxide (rGO, 3.0%) as the carbon source, tricresyl phosphate (TCP, 47.0%) as the plasticizer; sodium tetrakis[3,5-bis(trifluoromethyl)phenyl] borate (St-TFPMB, 1.0%) as the ion exchanger; and levofloxacinium-tetraphenylborate (LF-TPB, 5.0%) as the lipophilic ion pair. It showed a sub-Nernstian slope of 49.3 mV decade−1 within the LF concentration range 1.0 × 10−2 M to 1.0 × 10−5 M, with a detection limit of 1.0 × 10−5 M. The PVC coated electrode (C-CPE) showed improved sensitivity (in terms of slope, equal to 50.2 mV decade−1) compared to CPEs. After the incorporation of PVC paste on the modified CPE (P-CPE), the sensitivity increased at 53.5 mV decade−1, indicating such improvement. The selectivity coefficient (log KLF2+,Fe+3pot.) against different interfering species (Na+, K+, NH4+, Ca2+, Al3+, Fe3+, Glycine, Glucose, Maltose, Lactose) were significantly improved by one to three orders of magnitudes in the case of C-CPE and P-CPE, compared to CPEs. The modification with the PVC membrane coating significantly improved the response time and solubility of the LF-TPB within the electrode matrix and increased the lifetime. The constructed sensors were successfully applied for LF determination in pharmaceutical preparation (Levoxin® 500 mg), spiked urine, and serum samples with high accuracy and precision.

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