A Hafnium Oxide Based Voltammetric Platform for the Sensitive Determination of Octopamine

An electrochemical sensor was constructed by modification of a glassy carbon electrode (GCE) with nanoparticles of hafnium oxide (HfO₂) and multi-walled carbon nanotubes (MWCNTs) for the sensitive determination of octopamine. The platform (HfO₂NPs/MWCNTs/GCE) presented an improved anodic peak for octopamine at 0.65 V. The combination of HfO₂ and MWCNTs resulted in outstanding catalytic activity and enhanced the magnitude of the peak response. Results suggest that a three-electron oxidation occurs for the process of octopamine. Voltammetry of octopamine exhibited a dynamic linear response in the concentration range of 1.6×10⁻⁶∼4.8×10⁻⁵ M with a detection limit of 5.4×10⁻⁷ M for octopamine.