Electrochemistry and electrocatalysis of myoglobin intercalated in Mg2Al-Cl layered double hydroxide and ionic liquid composite material

A novel biocompatible nanocomposite prepared by Mg2Al-Cl layered double hydroxide (LDH) and ionic liquid (IL) 1-carboxyl-methyl-3-methylimidazolium tetrafluoroborate was used as the matrix for the immobilization of myoglobin (Mb). The IL-LDH-Mb composite was characterized by UV-vis adsorption spectroscopy and the results indicated that Mb retained its native structure in the IL-LDH nanocomposite. The IL-LDH-Mb bionanocomposite was modified on the surface of carbon ionic liquid electrode to get an Mb modified electrode. Electrochemical experiments showed that direct electrochemistry of Mb in the composite was realized with a pair of well-defined redox peaks appeared, which could be attributed to the specific microenvironment provided by layer structured LDH and high ionic conductive IL present for Mb molecule. The modified electrode exhibited good direct electrocatalytic ability to the reduction of trichloroacetic acid and hydrogen peroxide with good stability and reproducibility. Different kinds of real samples were detected by the modified electrode with satisfactory results. So the IL-LDH nanocomposite provided a novel and efficient platform for the immobilization of enzymes, which had potential applications in the fabrication of third-generation biosensors. (C) 2012 Elsevier B.V. All rights reserved.