Activated silica gel based carbon paste electrodes exhibit signal enhancement for quercetin

Highly-sensitive and rapid determination of protocatechuic aldehyde based on the electrochemical enhancement of activated silica gel

Analytical Methods ◽

10.1039/c4ay01816h ◽

2014 ◽

Vol 6 (21) ◽

pp. 8738-8743

Author(s):

Xuerong Chen ◽

Kangbing Wu ◽

Yikai Zhou

Keyword(s):

Silica Gel ◽

Electrochemical Method ◽

Rapid Determination ◽

Signal Enhancement ◽

Protocatechuic Aldehyde ◽

Highly Sensitive ◽

Activated Silica Gel

A highly-sensitive electrochemical method was developed for the determination of protocatechuic aldehyde (PAL) based on the remarkable signal enhancement of activated silica gel.

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Development of chemically modified carbon paste electrodes with transition metal complexes anchored on silica gel

Materials Chemistry and Physics ◽

10.1016/j.matchemphys.2016.11.021 ◽

2017 ◽

Vol 186 ◽

pp. 470-477 ◽

Cited By ~ 4

Author(s):

Bárbara B. Cazula ◽

Angélica M. Lazarin

Keyword(s):

Transition Metal ◽

Metal Complexes ◽

Silica Gel ◽

Transition Metal Complexes ◽

Carbon Paste ◽

Chemically Modified ◽

Carbon Paste Electrodes ◽

Modified Carbon Paste Electrodes

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Influence of the physical properties and handling of silica gel modified carbon paste electrodes on the phase transfer of solved Cu(II) ions

Analytica Chimica Acta ◽

10.1016/j.aca.2006.04.016 ◽

2006 ◽

Vol 571 (1) ◽

pp. 105-112 ◽

Cited By ~ 4

Author(s):

Axel Meyer ◽

Susanne Höffler ◽

Klaus Fischer

Keyword(s):

Physical Properties ◽

Silica Gel ◽

Phase Transfer ◽

Carbon Paste ◽

Carbon Paste Electrodes ◽

Modified Carbon Paste Electrodes

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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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