Modification of glassy carbon electrode with iron-terpyridine complex and iron-terpyridine complex covalently bonded to ordered mesoporous carbon substrate: Preparation, electrochemistry and application to H2O2 determination

Abstract In this paper, simple strategies for the modification of glassy carbon electrode (GCE) with iron-4″(phenyl)-2, 2″:6″, 2"-terpyridine complex (Fe-PTPY) and Fe-PTPY covalently bonded to ordered mesoporous carbon (OMC) are described. The Fe-PTPY/OMC modified GCE (Fe-PTPY/OMC/GCE) was prepared in a three steps strategy. In the first step, OMC modified GCE was prepared by simple casting. Then, PTPY ligand was attached directly to the electrode surface through electrochemical reduction of 4'(4aminophenyl)-2, 2':6', 2"-terpyridine (APTPY) diazonium salt. The modification was completed by iron attachment to the electrode surface through complex formation reaction with surface PTPY groups. The Fe-PTPY modified GCE (Fe-PTPY/GCE) was prepared in similar manner by omitting the first step of the above strategy. The reactions progress and the electrochemical behavior of the modified electrodes were studied using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The modified electrodes showed good electrocatalytic activity for reduction of H 2 O 2 . Using hydrodynamic amperometry, under optimum conditions, calibration plots for H 2 O 2 were linear in the ranges of 0.15–0.4 and 0.4–5.0 mM with slopes of 0.2743 and 0.2112 μA/mM on Fe-PTPY/GCE and 0.01–0.1 and 0.1–13.0 mM with slopes of 4.91 and 0.91 μA/mM on Fe-PTPY/OMC/GCE, respectively.