Electrochemical sensor based on a ZnO-doped graphitized carbon for the electrocatalytic detection of the antibiotic hydroxychloroquine. Application: tap water and human urine

Abstract

In December 2019, the world experienced a new coronavirus, SARS-CoV-2, causing coronavirus disease 2019 originating from Wuhan.The virus has crossed national borders and now affects more than 200 countries and territories. Hydroxychloroquine has been considered as a drug capable of treating COVID-19. The objective of this work is to establish a simple platform for electrocatalytic detection of hydroxychloroquine in human urine samples and pharmaceutical samples (tablets) using a ZnO@CPE sensor constructed by simple and inexpensive hydrothermal methods using a square wave voltammetry method. The best results are obtained in a PBS electrolyte with irreversible behavior of the hydroxychloroquine complement and controlled by diffusion coupled with absorption phenomena. The ZnO@CPE shifts the oxidation potential of hydroxychloroquine with the formation of a single very intense peak at the position of Epa = 0.5 V/(vs Ag/AgCl) with a shift is ΔEp = 0.1 V(vs Ag/AgCl) compared to the unmodified electrode. The obtained ZnO@CPE hybrid nanocomposite was characterized by different techniques and showed excellent electrocatalytic activity and higher active surface area compared to the bare carbon paste electrode. Under the optimized experimental conditions, the ZnO@CPE sensor showed good analytical performance for the determination of trace amounts of hydroxychloroquine, a wide linearity range from 10 –3 M to 0.8 × 10 –6 M with a very low detection limit in the range of 1.33 × 10 –7 M, satisfactory selectivity, acceptable repeatability and reproducibility. The calculated recovery and coefficient of variation for the two samples analyzed are very satisfactory, ranging from 97.6 to 102% and 1.2 to 2.3% respectively. The proposed applied method and the fabricated sensor offer the possibility to analyze traces of hydroxychloroquine in real human urine and water samples. Graphical abstract Strategy for the electro-oxidation reaction of hydroxychloroquine on the electro-catalytic surface of the ZnO@Carbon graphite electrode and real-time detection of hydroxychloroquine.

Alkaline earth metal stannate TSnO3 (T = Ca and Sr) entrapped functionalized carbon nanofiber composites: active electrocatalysts for the determination of hydroxychloroquine in environmental samples

“…This evidently substantiates that the occurrence of both Ca 2+ and Sn 4+ cations in the perovskite oxide and their hybridization with f-CNF not only augments the electronic conductivity, it further increases the electrochemical activity of CaSnO 3 /f-CNF modified GCE electrode that parades two electrons and two protons transfer. [76][77][78] The possible irreversible electrochemical oxidation mechanism of HCQ is given in Scheme 2.…”

An overview of electrochemical biosensors used for COVID-19 detection

“…However, voltammetric techniques may present limitations in detecting very low concentrations of analytes, which can be a disadvantage in applications that require high sensitivity, in addition to the necessity to use an electrochemical probe to carry out the measurements. [57][58][59] Electrochemical impedance spectroscopy (EIS) is a technique that can also be used to investigate interfacial properties related to biorecognition events that occur on the electrode surface. This technique has the advantage of requiring a small perturbation of the steady-state amplitude to detect changes in the charge transfer resistance (R ct ) or capacitance value.…”

“…However, voltammetric techniques may present limitations in detecting very low concentrations of analytes, which can be a disadvantage in applications that require high sensitivity, in addition to the necessity to use an electrochemical probe to carry out the measurements. 57–59…”

In Situ Electrochemical Development of Highly Charged TiO 2 -NPs Nanoparticles Decorated With Reduced Graphene Oxide For The Detection of Trace Chloroquine In Contaminated Human Urine And Serum Samples

“…2 eV) and fast recombination of conduction band electrons and valence electrons attached to reduced graphene oxide (TiO2@rGO) has attracted significant attention due to its remarkable properties and has been widely used in the field of electronics [20,21]. Including the fabrication of sodium-ion batteries [22] ,solar cells [23], catalysis [24], energy... [23,25] One of the main areas of research in the world remains the creation of new varieties of TiO2 @rGO hybrid materials to meet environmental criteria and also for the fabrication of electrochemical sensors and biosensors [20,26,27].…”