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•Electrochemical detection of amoxicillin (AMX)•Types of chemically modified electrodes for AMX detection.•Indirect electrochemical methods for AMX analysis.•Analysis of Amoxicilin in ...several real samples.
Amoxicillin (AMX) is among the most successful antibiotics used for human therapy. It is used extensively to prevent or treat bacterial infections in humans and animals. However, the widespread distribution and excess utilization of AMX can be an environmental and health risk due to the hazardous potential associated to its pharmaceutical industries effluents. Besides, their extensive use in food animal production may result in some undesirable residues in food, e.g. meat, eggs and milk. Consequently, at high enough concentrations in biological fluids, AMX may be responsible of various diseases such as nausea, vomiting, rashes, and antibiotic-associated colitis. For this reason, the detection and quantification of amoxicillin in pharmaceuticals, biological fluids, environmental samples and foodstuffs require new electroanalytical techniques with sensitive and rapid measurement abilities. This review discusses recent advances in the development of electrochemical sensors and bio-sensors for AMX analysis in complex matrices such as pharmaceuticals, biological fluids, environmental water and foodstuffs. The main electrochemical sensors used are based on chemically modified electrodes involving carbon materials and nanomaterials, nanoparticles, polymers and biological recognition molecules.
The purpose of this paper is to fabricate graphene oxide (GO) from carbon rods of spent (ZnC) batteries using a new optimized approach in electrochemical applications. The proposed method-based ...sonication for the recycling of carbon rods was adopted as a fast and economical process via a less aggressive pathway. The energy reaction time and explosion problems were avoided by the proposed protocol. The waste graphite powder (carbon rods) and the powder produced by the developed method-based sonication (SGO) were characterized by UV–Visible, XRD, FTIR and SEM. The electrochemical performance of the prepared SGO was evaluated by cyclic voltammetry (CV) and current-voltage (I–V) techniques. The results revealed that SGO has a higher electrocatalytic property compared to the graphene oxide by the standard Hummers method (HGO).
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∙Sonication-assisted oxidation and exfoliation process was recycled for graphene oxide (SGO) production.∙The carbon powder of (ZnC) batteries rods and its graphene oxide (SGO) were characterized.∙The energy and reaction time along with explosion problems were avoided by the proposed approach.∙Electrochemical performances of SGO were investigated and compared to the Hummers graphene oxide (HGO).
Ciprofloxacin (CIPRO) is a second-line antibiotic that belongs to the fluoroquinolone class. Over the years, the consumption of fluoroquinolones has increased exponentially due to their efficacy in ...treating several common infections. However, the increase in its residues can endanger human health and ecosystems, which requires its monitoring through the development of sophisticated technologies. In this study, a novel sensor for highly selective and rapid detection of CIPRO is fabricated. A facile strategy was employed to fabricate the electrode by impregnation of clay mineral on carbon paste electrode (Clay/CPE). The morphological features of the provided sensor were characterized by means of X-ray diffraction spectroscopy (XRD), Fourier-transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). Moreover, the electrochemical characterization of the Clay/CPE was performed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Compared with unmodified electrode, the oxidation peak current of CIPRO greatly increased at Clay/CPE indicating the excellent ability to promote electron transfer. Electrochemical measurements have been carried out using differential pulse voltammetry (DPV). Under optimized experimental conditions, the oxidation peak current was linear to the concentration of CIPRO in the range from 2.0 × 10− 7 to 5.0 × 10− 5 mol/L (r2 = 0.98) with a detection limit of 4.6 × 10− 8 mol/L (3 × σ/P). The practical applicability of the as prepared sensor was tested in the spiked human urine and pharmaceutical tablets with good recoveries. The work presented herein was significant as it can serve as tools for the analysis of antibiotics in wastewaters prior to being discharged into the environment since this kind of antibiotics can cause bacterial and genetic resistance in microbial populations present in water bodies, which can negatively affect human health.
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•Simple and cost-effective synthesis of clay microparticles for an electrochemical application.•The synthesized clay microparticles were characterized using XRD and FT-IR spectroscopy.•Clay microparticles was used to enhance the performances of CPE toward CIPRO electro-oxidation.•Clay/CPE has been successfully applied for electrochemical detection of CIPRO in tablets and urine samples.
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•A new “metal-antibiotic” complexes were synthesized and characterized.•The Job’s method of continuous variation was used.•The binding constants (K) of the complexes AMX − M (M = Cu, ...Fe and Zn) were calculated.•AMX − M complexes antibacterial activity was evaluated against E. coli.
Some bacteria have developed resistance to antibiotics that were once commonly used to treat them. Moreover, this resistance has become more and more massive and worrying. During this work, we succeeded in synthesizing “metal-antibiotic” complexes, combining as a ligand for the metals of Cu (II), Zn (II) and Fe (III). These complexes AMX − M (M = Cu, Fe and Zn) were characterized by UV–Vis spectrophotometry, IR spectroscopy, and electrochemical methods. Job’s method of continuous variation suggested 1:1 metals to ligand stoichiometry for all amoxicillin complexes. The binding constant/association constant (K) of the AMX with Zn(II), Cu(II), and Fe(III) were found to be 4.46 × 104, 7.17 × 102 and 7.65 × 102 L mol−1, respectively. The IR spectra shows that the ligands coordinated to the metal ions through amino, imino, carboxylate, β-lactamic and carbonyl groups. The electrochemical results proved that amoxicillin oxidation process can be delayed by transition metal complexation. After, the complex synthesis, the antibacterial activity of ligand and its metal complexes were evaluated against Escherichia. coli bacteria by antibiogram method. The results show that the metal-amoxicillin complexes have better antibacterial activity against Escherichia coli (E. coli) than the free ligand (amoxicillin) due to the AMX protection against oxidation after complexation.
An analytical method for the determination of Flubendiamide (FBD) was investigated for the first time in this study using disposable pencil graphite electrodes (PGE). A detailed study of the ...electrochemical properties of FBD was carried out in phosphate buffer solution (PBS, pH 7.0). The results showed a well-defined reversible system result from the transformation of FBD to the corresponding hydroxyl-derivative. The results showed a linear range from 1 to 500 µM (R
2
= 0. 9952), as well as detection limit of 0.53 µM. The PGE sensor was successfully applied for the detection of FBD in wastewater and white rice.
Graphene Oxide (GO) and Reduced Graphene Oxide (rGO) are an advanced carbon materials due to their excellent properties. This article presents a facile route to synthesize GO by an electrochemical ...exfoliation route of pencil graphite at ambient temperature. The developed process for graphite electrode exfoliation has lead to a stable multi-layer dispersion of GO/rGO mixture. The exfoliated graphene solution was sonicated for 35 minutes to obtain a uniform dispersion. The prepared product was characterized by Physical (XRD, UV-Vis, FTIR) and electrochemical (CV, EIS) techniques. The product characterization using XRD resulted in the (002) graphite characteristic diffraction peak at 2θ = 26,43° matching a d-spacing of 3,37Ǻ, as the coexistence of GO at (001) reflection signal with 2θ = 11,79° and rGO at 2θ = 23,84° corresponding to a d-spacing of 8,19 and 3,73Ǻ, respectively. The performance of the prepared graphene was tested based on the results of the electrochemical parameters (charge transfer, peak intensity, and reversibility…) of the Fe(CN)63−/4− redox system. This alternative method for graphene synthesis showed a good controllable oxidation level, which makes it an attractive precursor concerning sensing, by considering its interesting properties.
The electrochemical oxidation of ibuprofen was investigated at a montmorillonite-doped carbon paste electrode (Mt–CPE). A well-defined oxidation peak was observed at around 1.02V/AgCl in phosphate ...buffer (pH8). The experimental condition was optimized by varying chemical and electrochemical parameters. The oxidation peak current is linear to the ibuprofen concentration in the ranges 1.0×10−3–1.0×10−6molL−1 and 1.0×10−6−1.0×10−7molL−1 with a detection limit of 6.80×10−8molL−1. The precision (n=8) assessed as relative standard deviation (R.S.D.) were 1.24% for 1.0×10−6molL−1 and 1.07% for 4.0×10−5molL−1 respectively. Possible interferences were tested and evaluated in 1.0×10−5molL−1 ibuprofen in the presences of common organic and inorganic interfering agents. Based on its high sensitivity and good selectivity, the Mt–CPE was successfully applied to determine ibuprofen in river water and commercial tablets. The satisfactory obtained results confirm the applicability of this sensor in practical analysis.
•The working electrode was prepared by mixing montmorillonite and carbon electrode (Mt–CPE).•The montmorillonite catalyzes the electrooxidation of ibuprofen.•The Mt–CPE was used to determine ibuprofen using differential pulse anodic stripping voltammetry.•The influence of the chemical and electrochemical experimental variables was investigated.•The MtMT–CPE was investigated to detect ibuprofen in river water and commercial tablets.
In this study, a modified carbon paste electrode with silver particles (Ag–CPE) was used for ofloxacin (OFL) detection with enhanced over-potential for low concentrations. The incorporation of silver ...particles on carbon paste was confirmed by scanning electron microscopy. Electrochemical behavior of ofloxacin at carbon paste electrode (CPE) and Ag–CPE was studied using cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy. The OFL interaction with Ag+ was derived from the oxidation of silver during anodic scan has been investigated under different conditions. The strong binding affinity of Ag+ with 1.0 × 10−5 M OFL resulted in the upward shift of the OFL potential, which shifted potential from 0.85 to 0.95 V. The modification of carbon paste electrode by silver microparticles has enhanced the oxidation current with over-potential of OFL at low concentrations without a decrease of the current. The influence of the sweeping potential range on OFL oxidation was optimized. The calibration curve for ofloxacin at Ag–CPE is linear in the range from 4.0 × 10−6 to 1.0 × 10−3 M, and the detection limit was 9.47 × 10−7 M. Possible effects of inorganic ions and organic substances were investigated but did not cause any significant interferences. Furthermore, the repeatability, reproducibility, and stability of the present sensor were done with satisfactory results. The proposed method was successfully applied to OFL determination in tap water samples.
The electrochemical impedance spectroscopy (EIS) has been used to study the interaction between paraquat and carbon modified by silver (AgCPE) and silver particles‐impregnated natural phosphate ...(Ag/NPhCPE). This study was developed using spectrophotometry (UVVis) and infrared spectroscopy. The resulting interaction was controlled by adsorption at lower concentration (≤1.0×10−5 mol L−1) and by diffusion in the opposite case. Both electrodes are used to determining paraquat with a low detection limit (<1.0×10−12 mol L−1). The precision expressed as relative standard deviation RSD for the concentration level 1.0×10−5 mol L−1 of paraquat, (n=8) were 0.93 % and 1.1 % for Ag/NPhCPE and AgCPE respectively.
This paper reports on the use of electrochemical impedance spectroscopy (EIS) allied to copper (II) for the determination of 2,4‐dinitrophenylhydrazine (DNPH) at glassy carbon electrode (GCE). The ...experiment measurements were carried out in methanol at a potential of 0.3 V versus Ag/AgCl. The Nyquist plots were modeled with a Randle equivalent circuit, by identifying the charge transfer resistance as the relevant concentration dependent parameter. These measurements show that the impedance spectra of DNPH increased by the formation of non‐electroactive compound produced from specific interaction between DNPH and Cu (II), which will block the electron‐transfer process of the redox probe. Therefore, the proposed methodology offers a detection limit of 4.0×10−8 mol L−1. The proposed methodology was satisfactorily applied to determine DNPH in industrial water samples.
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