Synergistically enhanced peroxidase-like activity of Fe3O4/Ti3C2 MXene quantum dots and its application in colorimetric determination of Cr (VI)

• Published in: Sensors and actuators. B, Chemical Chemical, 2023-02, Vol.376, p.132979, Article 132979
• Main Authors: Cheng, Yonghua, Shen, Peng, Li, Xingchuan, Li, Xiaotian, Chu, Ke, Guo, Yali
• Format: Article
• Language: English
• Subjects: Chromium (VI); Colorimetric method; Density functional theory; Fe3O4 MNPs; MXene quantum dots
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2022.132979

The rational design of artificial nanozymes has become a research focus owing to its low cost and high sensitivity. Herein, we present a facile ultrasonic strategy for the preparation of Fe3O4@MXene quantum dots (Fe3O4@MQDs) hybrid material, showing an enhanced peroxidase-like activity relative to pure MQDs and Fe3O4 magnetic nanoparticles (MNPs). The catalytic mechanism of the Fe3O4@MQDs is studied by steady-state fluorometric analysis, revealing that Fe3O4@MQDs can effectively decompose H2O2 to produce reactive hydroxyl radicals (•OH). Furthermore, density functional theory calculations demonstrate that the dramatic catalytic activity of Fe3O4@MQDs derives from the active sites of interfacial Fe-Ti dimer, which can significantly activate the absorbed H2O2 and promote its decomposition into •OH. Accordingly, a sensitive colorimetric sensor is proposed to detect Cr (VI), displaying a low detection limit of 0.26 μM. This work opens up a new approach for the design and synthesis of MQDs-based peroxidase-like enzymes and demonstrates its great potential in the detection of environmental pollutants. •A novel Fe3O4@MQDs heterostructure was synthesized.•Peroxidase-like activity of Fe3O4@MQDs was significantly enhanced.•Experiment and DFT calculations revealed the possible reaction mechanism.•Colorimetric detection of Cr (VI) with a detection limit of 0.26 μM in the range from 0 to 60 μM.