Intrinsic peroxidase-like activity exhibited by cerium oxide nanoparticles and their application to glucose detection

In this paper, the stable and good water-soluble polyacrylic acid functioned cerium oxide nanoparticles (CeO2 NPs) were successfully synthesized and characterized by dynamic light scattering (DLS), FT-IR and XPS. The experimental results indicated that the prepared CeO2 NPs exhibit intrinsic peroxidase-like activity, which can catalyze the oxidation of 3,3,5,5-tetramethylbenzidine (TMB) in the presence of H2O2 to produce blue reaction. Electron paramagnetic resonance (EPR) and Raman techniques were used to investigate the catalytic mechanism. On the basis of H2O2 concentration-dependent peroxidase-like activity of CeO2 NPs, a simple, low cost and selectively colorimetric method was constructed for sensing of glucose. Under the optimal conditions, the linear range for the determination of glucose was 0.5-10 mmol/L with a limit of detection (LOD, 3 σ ) of 0.1 mmol/L. The RSD was 2.4% for 1.0 mmol/L glucose ( n = 11). The proposed method has been successfully used for determination of glucose in serum samples.