LAUSR

Nanomaterial-based artificial enzymes(nanozymes) have shown great potential for application in colorimetric sensing. In this paper, the nanocomposites of CeO2 and reduced graphene oxide(rGO) were fabricated via a one-pot hydrothermal process, in which CeO2 nanoparticles were well anchored on the surface of rGO. The prepared CeO2/rGO nanocomposites exhibited excellent catalytic activity for the oxidation of 3,3′,5,5′-tetra-methylbenzidine(TMB) in the presence of O2. Compared with the individual CeO2 nanoparticles, the nanocomposites had a higher affinity and adsorptivity towards the substrate TMB, which was due to the combination of rGO. In addition, based on the oxidase-like activity of CeO2/rGO nanocomposites, a facile and sensitive colormetric sensor for ascorbic acid(AA) was investigated. The detection limit of AA was low(0.15 μmol/L) and the linear detection range was between 0.5 μmol/L and 40 μmol/L. Furthermore, the colorimetric system was used for the detection of AA in medicine and food analysis, such as tablets, beverage and milk powder.