Electrochemical Determination of Chloroquine Phosphate in Real Samples Using a Diresorcinate‐1,10‐phenanthrolinecobalt(II)‐Modified Glassy Carbon Electrode

Abstract

Chloroquine phosphate (CQP) is used for malaria treatment. As it is facing increasing resistance, it needs continuous monitoring using sensitive and specific detection methods. In this work, a voltammetric sensor was prepared by electropolymerization of a diresorcinate‐1,10‐phenanthrolinecobalt(II) complex on a glassy carbon electrode (poly(DHRPCo)/GCE) which was followingly characterized. Compared with a bare GCE, CQP showed single well shaped irreversible oxidative peak at the poly(DHRPCo)/GCE. The peak current showed excellent linearity with CQP concentration in the range of 0.005–300.0 μ m with a detection limit of 0.39 n m . The response of CQP at poly(DHRPCo)/GCE was not influenced by the presence of amoxicillin, ciprofloxacillin and paracetamol in addition to its high stability and reproducibility. It was applied for detection of CQP in various real samples, including three brands of tablets, human blood serum, and urine samples. The detected amount in tablets were in the range 98.4–103.2 % of their labeled value. Spike recovery results in human blood serum, urine, and tablet samples were 99.35–100.28 %, 99.03–100.32 %, and 98.40–100.41 %, respectively. Interference recovery results with less than 4.60 % error, the lower limit of detection and the wider dynamic range than most of the previously reported methods validate the potential applicability of the proposed method for CQP determination in various real samples with complex matrices.

Highly Specific Voltammetric Detection of Cephalexin in Tablet Formulations and Human Urine Samples Using a Poly(2,4,6-2′,4′,6′-hexanitrodiphenylamine)-Modified Glassy Carbon Electrode

“…Square wave voltammetry was used for CLN quantification in tablet formulation and human urine samples due to its superior sensitivity, low detection limits, and capacity to differentiate across background currents. ,, The electrocatalytic effect of the poly(DPA) polymer film toward CLN oxidation is indicated by the peak current obtained at the poly(DPA)/GCE, as shown in Figure , being more than six times higher than the peak current recorded at the bare GCE with an overpotential decrease (Δ E ∼ 113 mV).…”

“…Spectrophotometry, hyphenated methods, and chromatography are among the common techniques reported for the determination of CLN in different samples. Unfortunately, all these methods need tedious sample preparation, are time-consuming, require complex analytical equipment, and consume large amounts of organic solvents (non-eco-friendly). , On the contrary, electrochemical methods are more appealing than conventional methods because they are easy to use, inexpensive, repeatable, very sensitive, quick to analyze, and environmentally safe. − …”

“…There have been attempts to use voltammetric techniques to determine CLN in various real samples. , Via increasing its compatibility, electron conductivity, and surface area, surface modification often enhances the electrochemical performance of a working electrode. − In this regard the use of conducting polymers as electrode modifiers has drawn a lot of interest due to their good chemical stability, electrical conductivity, reproducibility, improved sensitivity, excellent biocompatibility, electrocatalysis, and strong adhesion to the electrode surface compared with a conventional electrode. ,− Dipicrylamine (2,4,6-2′,4′,6′-hexanitrodiphenylamine) is a conducting polymer containing two trinitrobenzene units with secondary amine functional groups (−NH−), available for electropolymerization, and can be used as a sensor in electrochemical techniques; − for sensing purposes only limited work is found.…”