CoO-supported ordered mesoporous carbon nanocomposite based nanozyme with peroxidase-like activity for colorimetric detection of glucose

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 × 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 μM glucose. Further, the nanozyme catalyzing platform was used to detect glucose in human serums with good accuracy and reproducibility.