A colorimetric/electrochemical dual-mode sensor based on Fe3O4@MoS2-Au NPs for high-sensitivity detection of hydrogen peroxide

Hydrogen peroxide (H2O2) is closely related to many diseases and is often used as a target for disease diagnosis and treatment, so the research of H2O2 detection method has attracted much attention. Compared with the current single-signal detection methods commonly used, dual-mode detection has inherent self-verification and self-correction functions and is expected to provide more reliable and anti-interference detection results. In this work, a novel nanocomposite Fe3O4@MoS2-Au NPs with strong peroxidase activity was constructed for the first time, and on this basis, a colorimetric/electrochemical dual-mode sensor was successfully prepared. Concretely, the Fe3O4@MoS2-Au NPs could catalyze reduction of H2O2 to generate ·OH, leading to a significant electrochemical signal. At the same time, the color reaction of 3, 3′, 5, 5′-tetramethylbenzidine (TMB) by ·OH can be used to build a colorimetric sensor. In colorimetric and electrochemical sensing systems, the linear range was 1–120 μM. The detection limit (LOD) can reach as low as 109 nM and 80 nM, respectively. In addition, the sensor has been favorably used for the detection of H2O2 in normal human serum, and the recovery range was 87.55–113.13 %. In conclusion, this work provides an economical, sensitive and visualized H2O2 detection platform, which has a wide application prospects.