Nickel–cobalt double hydroxide nanosheets wrapped amorphous Ni(OH)2 nanoboxes: development of dopamine sensor with enhanced electrochemical properties

Abstract

Nickel–cobalt layered double hydroxides (NiCo-LDHs) were synthesized using a facile hydrothermal method and then wrapped around amorphous Ni(OH)₂ nanoboxes with intact shell structures. The morphology and shape of the Ni(OH)₂/NiCo-LDHs nanocomposites were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM) and X-ray diffraction (XRD). Cyclic voltammetry (CV) was used to evaluate the electrochemical performance of the Ni(OH)₂/NiCo nanocomposites modified electrode towards dopamine. With a potential of 0.22 V, the Ni(OH)₂/NiCo-LDHs modified electrode was used to determine dopamine by amperometry, showing a significant current response and a linear dependence (R = 0.9997) in the concentration up to 1.08 mM with a sensitivity of 83.48 μA mM⁻¹ cm⁻² and a low detection limit of 17 nM (signal-to-noise ratio of 3). In particular, the fabricated dopamine sensor showed excellent reproducibility, long-term stability and favorable anti-interference.