Application of polyphenazine films doped with metal nanoparticles for the measurements of antioxidant capacity

Evolution of Pt and Ag nanoparticles composites with polyphenazines onto ITO electrodes during the oxidation of H2O2 with ascorbic acid

“…4 Glassy carbon electrodes modified with polyphenazine conducting polymers and Pt or Ag nanoparticles were prepared. These electrodes were used to study the interaction between H2O2 and antioxidants, in trolox equivalents, which was similar for all electrodes studied, and agreed with previously reported data using other contrasted techniques [20]. Recently, sensors for H2O2 have been designed using a nanocomposite of cobalt(III) complex and MWCNTs [21] or using cerium nanoparticles, which have been demonstrated to neutralize free radicals [22].…”

“…Regarding poly-safranine (PS) and poly-phenosafranine (PPs), 10 mg of monomer were added to 40mL of 0.1 M PBS solution at pH7, and the polymerization was performed by cycling in the potential range 1.2V to -0.8V and a scan rate of 50 mV s -1 for 15 cycles. All of solutions were deoxygenated by nitrogen pumping for 10 minutes [20].…”

“…A platinum solution made of 5·10 -3 M hexachloroplatinic acid solution in 0.5 M H2SO4 was used while the bulk solution for silver was made of 1·10 -3 M silver nitrate solution in 0.5 M H2SO4 [20].…”

“…Prior to platinum deposition on the ITO electrodes, the surface has to be modified with polyphenazines. Polymerization of polyphenazines on ITO was carried out by cyclic voltammetry following the electropolymerization conditions previously reported in the literature [10,20] and 7 summarized in the previous section. Figure 2 shows the voltammograms recorded in the course of the electropolymerization.…”

“…For PPs and PS, the presence of the phenyl radical with free rotation causes a steric hindrance in the growth of the polymer and the layers of polymer reaches a limit. In the case of PS, after 20-25 cycles the polymer layer has a constant thickness probably due to the additional hindrance provided by the methyl groups of the molecule [20]. Figure 3 shows the SEM image of PNR after the electropolymerization on the electrode.…”