Synthesis of nanosized LDHs by Au colloidal nanoparticles as nuclei and its application for electroanalysis

• Smaller nanosized Au/Ni-Al LDHs with 10 ± 0.2 nm than ever were synthesized.
• The conductivity was improved as Au/Ni-Al LDHs/GCE.
• Au/Ni-Al LDHs/GCE exhibits higher sensitive detection for ascorbic acid.

Nanosized Ni–Al LDHs were synthesized via a hydrothermal method by using Au colloidal nanoparticles as nuclei for LDH growth, designated as Au/Ni–Al LDHs. Transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy were used to characterize the structure and morphology. N2 physisorption was performed to measure the specific surface area. Electrochemical impedance spectroscopy and cyclic voltammetry were introduced to investigate the electrochemical properties of Au/Ni–Al LDHs. The average size of Au/Ni–Al LDHs was small as 10 ± 0.2 nm, and the high BET surface area was obtained. The conductivity was improved as Au/Ni–Al LDHs modified glassy carbon electrode (GCE), compared to Ni–Al LDHs modified GCE. Ascorbic acid was used as a model molecule to study the electroanalytical properties of Au/Ni–Al LDHs modified GCE. The results exhibited that high sensitive detection was obtained.