carbon paste electrode was modified by disodium 2,4-diamino-7-methylbenzo[g] pteridine-5,10-dioxide to fabricate a sensor for potentiometric determination of vanadyl ion (vo2+) in aqueous medium. the new ligand was synthesized in three steps with high yield. the optimal composition of the carbon paste was made of graphite powder (64.5%), ionophore (16.6%), paraffin oil (17.8%), and sodium tetra...

In this paper, a modified expanded graphite composite electrode based on natural zeolitic volcanic tuff modified with silver (EG-Ag-Z-Epoxy) was developed. Cyclic voltammetry measurements revealed a reasonably fast electron transfer and a good stability of the electrode in 0.1 M NaOH supporting electrolyte. This modified electrode exhibited moderate electrocatalytic effect towards urea oxidatio...

Carbon paste electrode was modified by disodium 2,4-diamino-7-methylbenzo[g] pteridine-5,10-dioxide to fabricate a sensor for potentiometric determination of vanadyl ion (VO2+) in aqueous medium. The new ligand was synthesized in three steps with high yield. The optimal composition of the carbon paste was made of graphite powder (64.5%), ionophore (16.6%), paraffin oil (17.8%), a...

Edged plane pyrolytic graphite electrode (EPPGE) was modified with and without Prussian blue (PB) nanoparticles and polyaminobenzene sulphonated single-walled carbon nanotubes (SWCNTPABS) using the chemical deposition method. The electrodes were characterised using microscopy, spectroscopy and electrochemical techniques. Results showed that edged plane pyrolytic graphite-single-walled carbon na...

A chemically modified electrode was successfully fabricated by means of depositing a thin layer of Copper hexacyanoferrate (CuHCF) on an amine adsorbed gold nanoparticle graphite paraffin wax composite electrode using a new approach. The electrochemical characteristics of the modified electrode were studied using cyclic voltammetry and electrochemical impedance spectroscopy (EIS). The modified ...

A new silver nanoparticle modified screen-printed electrode was developed and applied to the simultaneous determination of Pb(II) and Cu(II). Two different types of silver nanoparticles with different shapes and sizes, Ag nanoseeds and Ag nanoprisms, were microscopically characterized and three different carbon substrates, graphite, graphene and carbon nanofibers, were tested. The best analytic...

Xanthine oxidase (E. C. 1.2.3.2) was immobilized by adsorption on electrochemically modified graphite plate to obtain an enzyme electrode. The current of the enzyme electrode in substrate (xanthine) solutions was found to be a result of the electrooxidation of H2O2 generated in the enzyme layer. The linearity of the amperometric signal was up to a substrate concentration of 65 microM at 0.6 V (...

Glucose oxidase (E. C. 1.1.3.4) was immobilized on electrochemically modified graphite to obtain an enzyme electrode. The working surface of the electrode was coated with gelatine to prevent desorption of the enzyme. In substrate (glucose) solutions the amperometric signal of the enzyme electrode was due to the electroreduction of H202 generated in the enzyme layer. The linearity of the electro...

Electrochemical studies of laccases from basidiomycetes, i.e., Trametes hirsuta, Trametes ochracea, Coriolopsis fulvocinerea, Cerrena maxima, and Cerrena unicolor, have been performed. Direct (mediatorless) electrochemistry of laccases on graphite electrodes has been investigated with cyclic voltammetry, square wave voltammetry as well as potentiometry. For all mentioned high potential laccases...

Nickel modified carbon fibre electrodes were prepared by electrochemical oxidation and partial reduction of a graphite fibre electrode with a slow linear potential sweep in 97% H 2 SO 4 solution followed by impregnation & ionexchange with Ni +2 species. The cyclic voltammetry of the modified electrode in an alkaline medium showed electrocatalytic activity towards methanol oxidation which is con...