Construction Of Carbon Paste Electrode Research Articles

Self-assembled monolayer of 2-(((5-mercapto-1,3,4-thiadiazol-2-yl)imino)methyl)phenol (MTP) on gold surface: A platform for impedimetric and potentiometric sensing of mercury(II)

2-(((5-mercapto-1,3,4-thiadiazol-2-yl)imino)methyl)phenol (MTP) was synthesized, self-assembled on the surface of gold (Au) electrode (Au-MTP) followed by characterization using Cyclic voltammetry (CV) and Electrochemical impedance spectroscopy (EIS). CV and EIS confirmed the formation of well-organized Au-MTP SAM free from defects and pinholes. Au-MTP was further utilized as a platform for sensing of Hg2+ using EIS. The results showed sensitive and selective response of Au-MTP towards Hg2+ in the linear concentration range from 1.0 × 10−10 M to 1.0 × 10−4 M with limit of detection (LoD) of 5.6 × 10−11 M. Furthermore, MTP was self-assembled on gold nanoparticles (AuNPs) and MTP bound gold nanoparticles (MTP-AuNPs) so obtained were used as modifier for construction of carbon paste electrode (CPE). Hg2+-CPE exhibited Nernstian response towards Hg2+ with slope of 28.3 mV/decade in the concentration range from 1.0 × 10−5 M to 1.0 × 10−1 M with LoD of 6.3 × 10−6 M. Both the Au-MTP EIS sensor and Hg2+-CPE were successfully applied for estimation of Hg2+ content in tap water samples.

The use of nanocomposite approach in the construction of carbon paste electrode and its application for the potentiometric determination of iodide

The use of nanocomposite approach in the construction of carbon paste electrode and its application for the potentiometric determination of iodide

Green and facile solvent-free synthesis of NiTe2 nanocrystalline material applied to voltammetric determination of antioxidant morin

Nanocrystalline nickel ditelluride, NiTe2, has been prepared mechanochemically using ball milling in an inert atmosphere at room temperature, starting from Ni34Te66 powder mixtures. Structural and microstructural characterization of the Ni34Te66 alloy was performed by X-ray powder diffraction analysis and transmission electron microscopy. The formation of a trigonal NiTe2 phase (with P-3 m1 symmetry) occurs along with 3 h, and the pure-phase sample with average crystallite size of about 18 nm is achieved with 6 h of milling. The nanocrystalline samples show a paramagnetic behavior at 2 K, with a magnetic moment decreasing at room temperature. The Ni34Te66 alloy containing 18 nm nanocrystallites of NiTe2 was applied in the construction of carbon paste electrodes to the voltammectric determination of morin, a phenolic and antioxidant compound present in red wines generally considered to act as UV protectant and free-radical scavenger. The electroanalytical response is linear from 0.014–32.0 μmol L−1 with a limit of detection of 0.0133 μmol L‒1 and a recovery range of 101–120 % (n = 3). The proposed sensor NiTe2/CPE was successfully applied to the determination of morin in high, medium and low polyphenols content red wines such as Tannat, Cabernet Sauvignon and Pinot Noir.

Comparative study between two fabricated potentiometric sensors to enhance selectivity towards ferrous ions

Electroanalytical methods are highly selective for measuring electrical quantities including the charge, potential and current with their relation to chemical parameters. They are widely applied in various fields such as biochemical analysis, industrial quality control and environmental monitoring. They have many advantages over other techniques in that they are not time consuming and are specific for certain oxidation states of certain elements which give these techniques high selectivity and sensitivity features. This paper is based on two parts: the first part describes the fabrication of screen‐printed electrodes (SPEs) modified with methyl red as electroactive material, while second part describes the preparation and characterization of Fe(II)–methyl red complex using various spectroscopic tools, the complex being used for the construction of carbon paste electrodes (CPEs). The two proposed electrodes were successfully applied for the determination of Fe(II) in water and pharmaceutical (pharovit) samples. The electrodes under investigation show potentiometric response for Fe(II) in the concentration range 8.0 × 10−7–1.0 × 10−2 and 5.0 × 10−7–1.0 × 10−2 M at 25°C for SPE and CPE, respectively, and the electrode response is independent of pH in the range 1.5–7.0. These sensors show Nernstian slopes of 29.1 ± 0.2 and 29.7 ± 0.16 mV decade−1 with detection limit values of 8.0 × 10−7 and 5.0 × 10−7 M for SPE and CPE, respectively. These electrodes show fast response time of 6 and 4 s and exhibit a lifetime of 100 and 30 days for SPE and CPE, respectively. The mechanism of chemical reaction between modifier and Fe(II) on the SPE surface was studied using infrared spectra, scanning electron microscopy and energy‐dispersive X‐ray analysis. The proposed potentiometric method was validated according to the IUPAC recommendations. The results obtained using the proposed sensors were comparable with those obtained with inductively coupled plasma analysis.

Carbon paste electrodes with electrolytic binder: Influence of the preparation method

AbstractA method for the construction of carbon paste electrodes (CPE) is described. Here ferrocene is used as the insoluble electroactive species, graphite powder as conductor and sulfuric acid as binder. The CPE thus prepared prevents ferrocenium ions from diffusing towards the bulk solutions. Voltammetric, chronopotentiometric and chronoamperometric experiments performed with these CPEs show that the different preparation methods yield different electrochemical parameters for the ferrocene–ferrocenium system.