Synthesis of non-peripheral amine substituted nickel(ii) phthalocyanine capped gold nanoparticles and their immobilization on electrode for the electrocatalytic oxidation of hydrazine

Abstract

This paper describes the synthesis of non-peripheral amine substituted nickel(II) phthalocyanine capped gold nanoparticles (4α-Ni^IITAPc-AuNPs) and their immobilization on 1,6-hexanedithiol (HDT) modified Au electrode for the determination of hydrazine. The high resolution transmission electron microscopy image shows that the synthesized Ni^IITAPc-AuNPs were spherical in shape with a diameter of 5 ± 2 nm. Then, they were self-assembled on HDT which was preassembled on an Au electrode. The attachment of 4α-Ni^IITAPc-AuNPs on HDT was confirmed by scanning electron microscopy, reflectance spectroscopy, cyclic voltammetry and electrical impedance spectroscopy. The 4α-Ni^IITAPc-AuNPs modified electrode was exploited for the oxidation of hydrazine. It shows an excellent electrocatalytic activity towards the oxidation of hydrazine by not only shifting its oxidation potential towards a less positive potential but also enhancing its oxidation current when compared to the bare Au electrode. The observed electrocatalytic activity was ascribed to the large surface area of the AuNPs modified electrode. Further, the voltammetric current response was increased linearly while increasing the hydrazine concentration in the range of 10–100 μM and a detection limit was found to be 5 × 10⁻⁸ M (S/N = 3).