The electrocatalytic oxidation of L-tyrosine was investigated on a gold nanoparticles self-assembled glassy carbon electrode (gold nanoparticles/cysteamine/glassy carbon) using cyclic voltammetry and differential pulse voltammetry. Cyclic voltammetry was carried out to study the electrochemical oxidation mechanism of L-tyrosine, which showed an irreversible oxidation process at a potential of 0...

A novel chemically modified electrode was constructed based on multi-walled carbon nanotubes, MCM48 molecular sieve composite modified glassy carbon electrode .The modified electrode showed that it can be used for simultaneous determination of acetaminophen (ACT) and codeine (COD), simultaneously. The measurements were carried out by the application of differential pulse voltammetry (DPV), cycl...

The direct electrochemical behaviour of peptide methionine sulfoxide reductase A (MsrA) adsorbed on glassy carbon and boron doped diamond electrodes surface, was studied over a wide pH range by cyclic and differential pulse voltammetry. MsrA oxidation mechanism occurs in three consecutive, pH dependent steps, corresponding to the oxidation of tyrosine, tryptophan and histidine amino acid residu...

This paper describes the development of screen-printed (SPE) and carbon paste (CPE) sensors for the rapid and sensitive quantification of naphazoline hydrochloride (NPZ) in pharmaceutical formulations. This work compares the electroactivity of conventional carbon paste and screen-printed carbon paste electrodes towards potentiometric titration of NPZ. The repeatability and accuracy of measureme...

A new sensitive sensor was fabricated for simultaneous determination of codeine and acetaminophen based on 4-hydroxy-2-(triphenylphosphonio)phenolate (HTP) and multiwall carbon nanotubes paste electrode at trace levels. The sensitivity of codeine determination was deeply affected by spiking multiwall carbon nanotubes and a modifier in carbon paste. Electron transfer coefficient, α, catalytic el...

This article is focused on the determination of lidocaine hydrochloride as a local anaesthetic drug. A potentiometric method based on modified screen-printed and modified carbon paste ion-selective electrodes was described for the determination of lidocaine hydrochloride in different pharmaceutical preparations and biological fluids (urine and serum). It was based on potentiometric titration of...

Rapid and facile preparation of the cheap modified electrode materials is an important parameter in development of the efficient electrochemical sensor for industrial scale production and mass-market usage. In the present work, the carbon paste electrode modified with multi-walled carbon nanotubes (MWCNTs) was prepared for sensitive determination of lead (Pb) ion in the presence of bismuth (Bi)...

Different types of charge storage mechanisms at unmodified graphite vs. glassy carbon electrodes in acid sulphate supporting solution containing potassium hexacyanoferrate (II) redox active electrolyte, have been revealed by electrochemical impedance spectroscopy and supported by cyclic voltammetry experiments. Reversible charge transfer of Fe(CN)6 redox reaction detected by assessment of CVs o...

graphene modified glassy carbon electrodes have been developed for the determination of calcium dobesilate in pharmaceutical formulations. the prepared graphene and cnts were used as a conductive substrate for electrochemical study of calcium dobesilate. the direct electrochemistry of calcium dobesilate showed a reversible cyclic voltammogram with a formal potential of 133 mv (vs. ag/agcl) for ...

The interface of a 1 : 2 molar choline chloride/ethylene glycol deep eutectic solvent with a glassy carbon electrode has been investigated by polarization modulation reflection-absorption spectroscopy (PM-IRRAS). Temporal spectral changes at open circuit potential show the experiments to be surface sensitive and indicate slow adsorption of electrolyte molecules on the electrode surface. In situ...