Poly(vinylferrocenium) perchlorate–polyaniline composite film-coated electrode for amperometric determination of hydroquinone

Abstract

Poly(vinylferrocenium) perchlorate-polyaniline (PVF + -PANI) composite film was synthesized electrochemically on Pt electrode in a methylene chloride solution containing a mixture of poly(vinylferrocene) (PVF) polymer and aniline monomer. PVF + polymer in the composite film was used as an electron transfer mediator. The composite coating showed significant electrochemical activity towards hydroquinone (HQ) at pH 4, with high sensitivity and a wide linearity range. The interaction of HQ with PVF + and PANI homopolymer films was investigated electrochemically and spectroscopically. HQ molecules are accumulated on the electrode surface due to trapping by both polymers in the composite film and then oxidized catalytically by PANI. The most significant contribution of PVF + polymer is that it facilitates electron transfer in the composite film. The linear response range was found to be between 1.60×10 −4 mM and 115 mM (R 2 =0.999) at 0.45 V vs saturated calomel electrode. The limit of detection (LOD) was 4.94×10 −5 mM.

Investigation of the behavior of hydrogen‐bonded phenolic compounds and their determination by using poly(vinylferrocenium)–polyaniline composite film

“…Therefore, it is possible to predict that the response of TotPh could be due to two–Ct and Hq‐based essential hydrogen‐bonded clusters. While the upper limits of linearity ranges were 50.0 mM for Ct (Table ) and 115 mM for Hq, this value is, on the other hand, above 600 mM for TotPh due to the construction of intermolecular hydrogen bonds among phenolic compounds (Table ). It is interesting that the intermolecular hydrogen bonding prevent degradation of PANI film even in the presence of Ph and Rs.…”

“…As seen in Figure (B), both films (PANI and PVF + –PANI) have two linear fragments with different slopes for the determination of TotPh. This observation may arise from the presence of four different phenolic compounds in the TotPh solution because a similar property is not observed in the individual determination of Ct [Figure (A)] and Hq . To determine the contributions of Ph and Rs to the response of TotPh, the amperometric I – t curves were recorded under their optimum conditions on PANI‐coated electrodes.…”

“…This observation may arise from the presence of four different phenolic compounds in the TotPh solution because a similar property is not observed in the individual determination of Ct [ Figure 6(A)] and Hq. 59 To determine the contributions of Ph and Rs to the response of TotPh, the amperometric I-t curves were recorded under their optimum conditions on PANI-coated electrodes. Figure 9 shows the variation of current with concentration for Ph and Rs.…”

Electrode Prepared with Combination of Different Conductive Polymers for Hydroquinone Determination in River Water

“…TBAP used as a supporting electrolyte in non-aqueous media was obtained by the reaction of tetrabutylammoniumhydroxide (TBAOH) (40% aqueous solution, Sigma-Aldrich) with perchloric acid (BDH) and recrystallized in 1:9 (v:v) water and ethyl alcohol solution, dried at 120°C under vacuum for 12 h and stored under nitrogen. 24 Buffer solutions (pH 1.0-6.5) were prepared by using NaHSO 4 (Merck) and Na 2 SO 4 (Merck) for amperometric experiments in aqueous media. HQ solutions were prepared in the sulfate buffer solution (SBS, pH 2.0).…”

“…As a result, because modified film structure contains many -NH, -N and -NH 2 sites, HQ molecules can form hydrogen bonds at these sites that originate from PANI and PDAB. 24,26 In ad- dition, HQ molecules not only form hydrogen bonds but also cause reduction of PANI film 24 and provide continuous oxidation of HQ over synthesized film.…”