Electrochemical Detection of the Different Species of Levofloxacin Using PVC, Carbon Paste and Screen-Printed Electrodes: Effect of pH

Ghani, Nour ElDin T. Abdel; Abdel‐Haleem, Fatehy M.; Mahmoud, Sonia; Nashar, Rasha M. El

doi:10.1007/s41664-018-0056-6

Cited by 3 publications

(11 citation statements)

References 23 publications

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“…The continuous decrease in potential with pH increase is due to the decrease in the number of protons (H+), the higher amount of hydroxide at high pH values, and as a result the presence of the different LF species at the different values. This behavior was observed earlier for LF [31], and ciprofloxacin [57]; it can be understood in terms of the presence of many LF forms (LF ± , LF, LF + , LF 2+ , and LF − ) that can exist with different ratios at different pH [31][32][33]. Therefore, measurement solutions should be buffered to control species existence with a certain ratio to expect and obtain a confident response of the electrode.…”

Section: Effect Of Phmentioning

confidence: 52%

“…The solution was then filtered, washed with distilled water, dried at room temperature, and finally ground to a fine powder. The stoichiometry and chemical composition of the obtained precipitated ion-pair (LF-TPB) was identified and ensured by (C, H, N) elemental analysis [31].…”

Section: Preparation Of the Lf-tpb Ion-pairmentioning

confidence: 99%

“…The addition of 1% CD as a modifier in sensor 5 did not improve the response, compared with sensor 4, Figure 4a. Generally, the sub-Nernstian and small concentration range that is observed for different PVC sensors is due to different reasons: first is the presence of LF species in different forms (LF ± , LF, LF + , LF 2+ ) [30][31][32][33]; the second reason is the low solubility of the ion-pair in the plasticizer and in the membrane cocktail which limit the mobility of the ions within the membrane and limit the response [1]; the third reason is the presence of the inner filling solution that causes inwards and outwards migrations that cause the limited concentration range [1].…”

Section: Optimization Of the Pvc Membrane Layermentioning

confidence: 99%

“…We chose pH 2.2 and 4.1 to study the sensor response toward cationic species of LF. At low pH values, LF exists as LF + or LF 2+ , with a low amount in the LF ± form [31][32][33].…”

Section: Effect Of Phmentioning

confidence: 99%

“…The Morf water layer test was used to study the probability of water penetration to the coated electrode surface and relate that to the selectivity. The effect of the pH on the response characteristics of these new designs was studied in detail and related to selectivity, linear dynamic range and detection limit [31]. More interestingly, the constructed sensors were successfully applied for the LF determination in blood serum, urine, and commercial formulations (Levoxin ® 500 mg, Cairo, Egypt) with high sensitivity.…”

Section: Introductionmentioning

confidence: 99%

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

Abdel‐Haleem

Mahmoud

Abdel-Ghani

et al. 2021

Sensors

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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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Section: Effect Of Phmentioning

confidence: 52%

Section: Preparation Of the Lf-tpb Ion-pairmentioning

confidence: 99%

Section: Optimization Of the Pvc Membrane Layermentioning

confidence: 99%

“…We chose pH 2.2 and 4.1 to study the sensor response toward cationic species of LF. At low pH values, LF exists as LF + or LF 2+ , with a low amount in the LF ± form [31][32][33].…”

Section: Effect Of Phmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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