Electrochemical Oxidation of Methionine Mediated by a Fullerene‐C₆₀ Modified Gold Electrode

Abstract

The usefulness of a C 60 -fullerene modified gold (Au) electrode in mediating the oxidation of methionine in the presence of potassium ions electrolyte has been demonstrated. During cyclic voltammetry, an oxidation peak of methionine appearing at þ 1.0 V vs. Ag/AgCl was observed. The oxidation current of methionine is enhanced by about 2 times using a C 60 modified gold electrode. The current enhancement is significantly dependent on pH, temperature and C 60 dosage. Calibration plot reveals linearity of up to 0.1 mM with a current sensitivity of close to 50 mA L mol À1 and detection limit of 8.2 Â 10 À6 M. The variation of scan rate study shows that the system undergoes diffusion-controlled process. Diffusion coefficient and rate constant of methionine were determined using hydrodynamic method (rotating disk electrode) with values of 1.11 Â 10 À5 cm 2 s À1 and 0.0026 cm s À1 respectively for unmodified electrode while the values of diffusion coefficient and rate constant of methionine using C 60 modified Au electrode are 5.7 Â 10 À6 cm 2 s À1 and 0.0021 cm s À1 respectively.

The electrochemical effect of different temperatures on sodium saccharine in blood medium using modified working electrode CNT/GCE by cyclic voltammetry

“…It was found that the cathodic current peak was enhanced gradually at the range of temperature from 29 to 40°C. Figs 2 and 3 show the plot of Ln(I pc ) of NaSc versus reciprocal of temperature on GCE and CNT/GCE respectively, which is found to be fairly linear in agreement with thermodynamic expectation of Arrhenius equation; see Eqs (1) and (2) [17][18][19]. Also, the results of anodic current peaks are represented in Figs 4 …”

“…NaSc in blood medium was studied at different temperatures using each of GCE and modified GCE with CNT using cyclic voltammetric technique to determine the physical chemistry properties in terms of activation energy and thermodynamic parameters using Arrhenius equations [17][18][19] and Eyring equations [20][21][22], respectively.…”

Electrochemical and piezoelectric monitoring of taurine via electropolymerized molecularly imprinted films

“…Figure 2 shows a typical CV recorded during electropolymerization of l ‐methionine in presence of taurine on EQCM electrode (A) and in absence of taurine (B) (NIP). An oxidation peak appears at 0.320 V in NIP, which shifts a little to 0.306 in presence of taurine in imprinting polymerization mixture in MIP film, and a reduction peak appeared at 0.856 V in the CV of NIP film, which shifted to 0.848 V in MIP film corroborating the redox behavior of methionine to methionine sulfoxide and sulfone and reduction involving 1H + /1e − mechanism . An increase in peak current was observed for first 3 cycles in NIP and declines in further cycles.…”

Use of Nano-Sensors of the Interferences between Pb((II) with Each of Mg(II), Zn(II), Mn(II), Ca(II), Co(II) and PO4-3 in Blood Medium: An Electrochemical Study

“…A mechanical attachment technique was employed [18,19]. This technique included abrasive application of MWCNT nanoparticles at the clean surface of GCE, forming an array of MWCNT nanoparticles as MWCNT/GCE which immerse in 10 mL of electrolyte or blood sample in the cyclic voltammetric cell.…”