Analytical & Bioanalytical Electrochemistry
Volume:15 Issue: 10, Oct 2023

In the current study, outdated Ampicillin drug (AMP) was assessed as a potent and environmentally friendly corrosion inhibitor for 60Cu-40Zn brass by gravimetric analysis, in nitric acid solution in a concentration range of 0.5M-2M. The findings revealed that AMP exhibited high corrosion inhibition performance, and its efficiency increased with the increase of its concentration and the concentration of nitric acid. In addition, potentiodynamic polarization (PDP) curves, electrochemical impedance spectroscopy (EIS), and surface analysis were conducted in 0.5 M HNO3 solution. Ampicillin was found to act as a mixed-type inhibitor, and its inhibitory efficiency increased with the addition of AMP up to 92% at its optimal concentration of 10 mM. However, it decreased slightly with increasing temperature. The adsorption thermodynamic parameters demonstrated that the medicine adsorbed onto a brass surface in accordance with the Langmuir isotherm, via physisorption and chemisorption mechanism. Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX) and   FT-IR/ATR analysis clearly evidenced the strong adsorption of AMP onto the brass surface, leading to higher corrosion resistance of the brass alloy in the inhibitive solution. Theoretical parameters of drug molecules were computed, using density functional theory (DFT) and Fukui indices, to better understand the adsorption mechanism of AMP molecules onto the brass surface. A close agreement between quantum calculations and experimental results was observed.

A lactate biosensor has been designed for the detection of lactate in a real sample. A combination of composite material comprising of multi-walled carbon nanotubes (MWCNTs) and zinc oxide nanoparticles has been used as working electrode, which were deposited on gold (Au) wire. This was treated as working electrode for the preparation of a LDH-based amperometric biosensor along with acetyl coenzyme, which acts as the mediator to enhance electron transportation. The biosensor showed excellent results in terms of stability, response time, and sensitivity. The sensitivity of the biosensor is 4.487 mA/µM and its linearity is between 10 µM and 100 µM. The biosensor has a 0.67 µM limit of detection with a response time of 8 sec. The optimal temperature is 35°C, and the optimal pH is 8. All the results confirmed that the ZnO/MWCNTs/Au electrode, along with acetyl coenzyme, acts as a suitable matrix for the purpose of immobilizing LDH enzymes for the formation of lactate biosensors.

A novel ion-imprinted polymer (IIP)-based potentiometric sensor is introduced for precise determination of Ni2+ ions. The imprinted polymer was prepared using methacrylic acid and ethylene glycol dimethacrylate as functional monomer and cross-linker. This potentiometric sensor is a carbon paste electrode, composed of IIP particles (4%), graphite (64%), n-eicosane (25%), and sodium tetra phenyl borate (5%) in its optimum condition. The sensor exhibited a Nernstian slope of 29.1±0.4 mVdecade−1 in the concentration range of 1.0×10−6 to 1.0×10−1 mol L−1 with a detection limit of 5×10−7 mol L−1. The sensor demonstrated a stable potential response in the pH range of 4–7 and fast response times below 1 minute. Thanks to the high selectivity of the IIP-based probe, common interfering species had almost no effect on its response toward Ni2+ ions. The proposed sensor was prosperously applied to analyze the Ni2+ content of real sea, lake, and industrial water samples.

This paper covers the synthesis and characterization of tetraamino Zinc(II) metallophthalocyanine (Zn(II)TAPc) using spectroscopic and electrochemical techniques. The electrochemical determination of dopamine (DA), ascorbic acid (AA) and uric acid (UA) was investigated using composite modified MWCNT-Zn(II)TAPc/GCE, due to their excellent conductivity, electrons transfer ability compared to the bare glassy carbon electrode (GCE), and because the charge transfer rate increases with multiwalled carbon nano tubes (MWCNT) on the surface of GCE. As a result, electrochemical sensing of bioanalytes was investigated on MWCNT-Zn(II)TAPc/GCE, and the analytical profile of micro molar concentration (µM) of DA is in the linear range of 0.1 to 1.1 µML-1 with LOD is 0.033µML-1, sensitivity of 14.063 µAµML-1 and the electro analytical sensing of AA and UA while using modified composite electrode for AA the linear range of 0.2-0.7 μmol L−1, LOD of 0.066μmol L−1 and sensitivity  54.821 μAμM−1 cm−2, for UA the linear range of 0.05–1.2 μmolL−1, lower detection limit of 0.066 μmolL−1 and sensitivity of 0.515 μAμM−1 cm−2, The MWCNT-Zn(II)TAPc/GCE shows good repeatability, stability and reproducibility.

The objective of this research is to enhance the value of the clove tree (Syzygium aromaticum), an aromatic and medicinal plant found in Senegal. The focus is on assessing the inhibitory effect of the essential oil extracted from clove on C24 carbon steel in a 1M HCl medium. In the initial phase of the study, essential oil was extracted from the cloves through hydrodistillation utilizing a Clevenger-type extractor. These extractions yielded an average extraction rate of 11.7%, a notably commendable figure when compared to various data reported in existing literature. Subsequently, the extracted essential oil underwent characterization employing standard chromatographic techniques (GC/IR, GC/MS). This allowed for identification of the chemical compounds constituting the essential oil, with major compounds identified as Eugenol (64.97%), Caryophyllene (24.15%), and Acetyleneugenol (6.19%). The research delved into investigating the inhibitory impact of clove essential oil on C24 steel in a 1M HCl medium using electrochemical techniques. The outcomes of this investigation indicated an optimal efficacy of 88.52% for an essential oil concentration of 4g/L at 290K. Furthermore, the study assessed the influence of temperature on the inhibitory properties of the essential oil across a temperature spectrum of 290 to 338 K. Within this temperature range, a marginal reduction in efficiency was noted with increasing temperature, ultimately 79.92% at 328 K. Subsequently, thermodynamic parameters were computed. The graphical representation of the distinct isotherms demonstrated that the adsorption of the essential oil adhered to the Langmuir isotherm. The results underscored a blended adsorption characteristic of this essential oil.

Here, the synthesized zinc oxide nanoparticle and characterized with XRD and SEM techniques. The carbon paste electrode was modified by using prepared nanoparticles with electrochemically polymerized by treating with 25mM Congo red and sensing environmental pollutants. The Poly (Congo red) Zinc oxide modified carbon paste [PCRZOMCPE] brings an enhanced sensitivity at electrochemical detection of catechol (CC) by using cyclic voltammetry (CV); the parameters like pH, sweep rates and concentration study was carried out, the PCRZOMCPE is applied for the simultaneous determination of CC and hydroquinone (HQ) then the detection limit and quantification value for CC is established to be 9.39µM and 31.30 µM respectively and the electrode showed excellent sensitivity and selectivity towards electrochemical examination of CC.