Well-redispersed ceria nanoparticles: Promising peroxidase mimetics for H2O2 and glucose detection

Well-redispersed ceria nanoparticles (CeO2 NPs) were synthesized by a simple hydrothermal method. The prepared CeO2 NPs exhibited excellent catalytic activity towards classical peroxidase substrate 3,3,5,5-tetramethylbiphenyl dihydrochloride (TMB·2HCl) in the presence of H2O2, based on which a colorimetric method that is highly sensitive and selective was developed for glucose detection. The composition, structure, morphology and peroxidase-like catalytic activity of CeO2 NPs are investigated in detail by using X-ray diffraction (XRD), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectrometer (FT-IR), thermal analysis (TG) and UV-vis absorption spectroscopy. According to this method, the detection of H2O2 and glucose are in linear range from 6.0 × 10−7 to 1.5 × 10−6 mol L−1 and 6.6 × 10−6 to 1.3 × 10−4 mol L−1, with the detection limit down to 5.0 × 10−7 mol L−1 H2O2 and 3.0 × 10−6 mol L−1 glucose, respectively. Further, this simple, cheap, highly sensitive and selective colorimetric method for glucose detection was successfully applied for the determination of glucose in human serum samples.