Synthesis Of Nanosized Ldhs By Au Colloidal Nanoparticles As Nuclei And Its Application For Electroanalysis

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.The electroanalytical properties of Au/Ni-Al LDHs modified glassy carbon electrode(Au-LDHs/GCE) were carried out by using Ascorbic acid(AA) as a non-enzymatic model molecule. The results exhibited that more sensitive detection was obtained compared to Ni-Al LDHs modified glassy carbon electrode(LDHs/GCE).In addition, hemoglobin(Hb) was used as an ideal enzymatic model molecule for the investigation of direct electrochemistry of redox protein with GCE. Results showed that both the synthesized LDHs showed an obvious promotion for the direct electron transfer. Based on the catalytic ability of the immobilized Hb, modified electrode Au-LDHs-Hb/GCE exhibited more excellent electrocatalytic behavior towards the reduction of H2O2 than LDHs-Hb/GCE.