Nano-based mimetic enzymes have been widely used for catalysis due to their large specific surface area, high stability and activity. Herein a new nanocomposite cobalt oxide (CoO) assembled onto ordered-mesoporous carbon (CoO-OMC) is reported, which shows good peroxidase-like activity upon the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) by hydrogen peroxide (H2O2). The apparent maximum velocity (V-max) and apparent Michaelis-Menten constant (K-m) were 2.66 x 10(-7) M s(-1) and 3.29 mM, respectively. Since the glucose oxidation and TMB oxidation can be bridged by the quantitation of H2O2, therefore, coupled with glucose oxidase, the as-prepared CoO-OMC nanocomposite was applied for the colorimetric detection of glucose in the linear range of 0.1-5.0 mM and the limit of detection of 68 mu M glucose. Further, the nanozyme catalyzing platform was used to detect glucose in human serums with good accuracy and reproducibility.