A Cu2(OH)3Cl-CeO2 nanocomposite with peroxidase-like activity, and its application to the determination of hydrogen peroxide, glucose and cholesterol

A nanomaterial of the chemical composition Cu 2 (OH) 3 Cl-CeO 2 and with a large surface area is shown to be a viable peroxidase mimetic. It was synthesized by co-precipitation of an aqueous solution containing Ce(III) chloride, Cu(II) chloride and hexamethylenetetramine by adding an ionic liquid. The material was characterized by scanning electron microscopy and X-ray powder diffractometry. The composite possesses peroxidase-like activity and catalyzes the oxidation of the peroxidase substrate 3,3′,5,5′-tetramethylbenzidine by H 2 O 2 to produce a blue product. Based on this finding, a simple, rapid and selective colorimetric method was worked out for the determination of glucose and cholesterol by using the respective oxidases and by quantifying the H 2 O 2 formed. Both glucose and cholesterol can be determined by this method at levels as low as 50 µM. We found that the newly synthesized Cu 2 (OH) 3 Cl-CeO 2 composite material possesses intrinsic peroxidase-like activity, and this finding was applied to design a rapid and selective colorimetric assay for H 2 O 2 , glucose and cholesterol.