Facile decoration of graphene oxide with Cu(II)/1H-benzotriazole complex via π–π interaction for sensitive determination of hydrogen peroxide and hydroxylamine

Cu(II) and 1H-benzotriazole (BTA) formed stable complex, denoted as Cu-BTA, in aqueous solution. Cu-BTA can be easily anchored on the surface of graphene oxide (GO) via π–π stacking interaction. The obtained nanocomposite of Cu-BTA and GO, denoted as Cu-BTA@GO, was characterized with cyclic voltammetry (CV) and Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). Cu-BTA@GO and multiwalled carbon nanotube (MWCNT) were used to modify glassy carbon electrode (GCE). The obtained modified electrode, denoted as Cu-BTA@GO/MWCNT/GCE, exhibited excellent catalytic capability toward the reduction of hydrogen peroxide and the oxidation of hydroxylamine (HA). Cu-BTA@GO/MWCNT/GCE presents wide linear range for the determination of H₂O₂ and HA, which is 1.0 μM–2.15 mM and 1.0 μM–1.0 mM, respectively. The limit of detection (LOD) for the determination of H₂O₂ and HA is 0.1 μM and 0.31 μM, respectively. The large electroactive surface area and the extraordinary electrocatalytic capability of Cu-BTA@GO/MWCNT/GCE are probably due to the combination of Cu-BTA/GO and MWCNT.