Non-enzymatic glucose sensor based on Au nanoparticles decorated ternary Ni-Al layered double hydroxide/single-walled carbon nanotubes/graphene nanocomposite

A novel highly sensitive non-enzymatic glucose sensor was constructed based on gold nanoparticles decorated ternary Ni-Al layered double hydroxide/single-walled carbon nanotubes/graphene nanocomposite (Au/LDH-CNTs-G). The materials were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, UV-vis diffuse reflectance spectra and Raman spectra, and the sensing performance was investigated by electrochemical impedance spectroscopy, cyclic voltammetry and amperometric response. The results revealed that Au/LDH-CNTs-G nanocomposite modified glassy carbon electrode exhibited remarkable electrocatalytic performance toward glucose oxidation, with a wide linear range from 10 μM to 6.1 mM, a high sensitivity of ∼1989 μA·mM−1·cm−2 and a low detection limit of 1.0 μM based on a signal to noise ratio of 3, which was mainly attributed to the combined effects of enhanced electrical conductivity originating from three-dimensional intertwined CNTs-graphene network, good accessibility to active reaction sites from NiAl-LDH and more electron transfer passages provided by Au nanoparticles highly dispersed on the surface. What's more, as-constructed non-enzymatic sensor showed good reproducibility, repeatability, stability and anti-interference property, and was also used to practically analyze glucose concentration in human serum samples.