Peroxidase‐Mimetic and Fenton‐Like Activities of Molybdenum Oxide Quantum Dots

Molybdenum oxide nanomaterials have become a popular nanomaterial while its catalysis behavior especially the bio‐catalysis property is little understood, even though molybdenum has been employed as a key cofactor in several important enzymes in biological system. On the basis of these, the Fenton and peroxidase‐like property of molybdenum oxide quantum dots (MoO x QDs) with mixed valence state was carefully investigated using tetramethylbenzidine (TMB) and methyl orange (MO) as the substrates. The results showed that MoO x QDs not only serve as a Fenton reagent, degrading MO to colorless products, but also exhibit intrinsic peroxidase‐mimetic activity, oxidizing TMB to the oxidized state oxTMB. The catalysis mechanism of MoO x QDs is that MoO x QDs can facilitate the decomposition of H 2 O 2 and a large amount of radicals was generated, leading to MO decomposing and TMB oxidizing subsequently. Inspired by the findings, a visible method was developed for sensitive and selective detection of H 2 O 2 and glucose, and the limit of detection for H 2 O 2 and glucose is 7.75 μM and 8.95 μM (3σ/K), respectively. Moreover, glucose content in human serum samples was successfully determined by the proposed visible method, and the results are consistent well with those obtained by handheld glucose meter, suggesting a high accuracy of the present method.