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

Abstract

Well-redispersed ceria nanoparticles (CeO 2 NPs) were synthesized by a simple hydrothermal method. The prepared CeO 2 NPs exhibited excellent catalytic activity towards classical peroxidase substrate 3,3,5,5-tetramethylbiphenyl dihydrochloride (TMB$2HCl) in the presence of H 2 O 2 , 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 CeO 2 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 H 2 O 2 and glucose are in linear range from 6.0 Â 10 À7 to 1.5 Â 10 À6 mol L À1 and 6.6 Â 10 À6 to 1.3 Â 10 À4 mol L À1 , with the detection limit down to 5.0 Â 10 À7 mol L À1 H 2 O 2 and 3.0 Â 10 À6 mol L À1 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.

Cerium oxide nanoparticle: a remarkably versatile rare earth nanomaterial for biological applications

“…10,[43][44][45][46] Although the mechanisms of these activities were not thoroughly studied and fully understood, one could hypothesize that the properties resemble the mechanism of catalytic activities observed in nonbiological systems. These enzyme-mimetic properties make CeONPs useful in biotechnology and therapeutics.…”

“…Furthermore, based on this property the group developed a facile colorimetric method for glucose detection. 45 The peroxidase-like activity provides CeONP broad potential applications in environmental chemistry, biotechnology and medicine.…”

Ceria Nanoparticles as Enzyme Mimetics

“…The utilization of nanoceria as oxidase under some special circumstances was also reported. Recently, nanoceria have been used for several applications either in biotic conditions or abiotic conditions, such as antioxidants, [63][64][65] capping [36] and neuroprotection agents, [66][67][68][69][70][71][72] biosensors, [23,28,73] immunoassays, [31,32,74] color indicator [27,[75][76][77][78][79] and so on.…”

“…Previous studies demonstrated that nanoceria possessed enzyme-like catalytic activity and were stable over a wide range of pH values and temperatures compared with natural enzyme horseradish peroxidase. [27,28] One of our ongoing works implies that activated nanoceria could maintain their catalytic activity at a higher level than native SOD at harsh pH and temperature conditions. Therefore, nanoceria present a promising enzyme mimetics for future applications.…”

“…[26] Compared with natural enzymes, nanoceria are generally considered to have better heat and pH stability. Studies conducted by Jiao et al [27] and Tian et al [28] demonstrated that nanoceria possessed enzyme-like catalytic activity and chemical stability over a wide range of pH values and temperatures compared with natural enzyme horseradish peroxidase. However, several reports showed that nanoceria would gradually lose their activity due to the changed surface chemistry during the catalysis, [29,30] and the regeneration of catalytic activity may take several days or even weeks.…”