A simple hydrothermal one-step synthesis of 3D-MoS2/rGO for the construction of sensitive enzyme-free hydrogen peroxide sensor

Hydrogen peroxide (H 2 O 2 ) is an important intermediate in biological and environmental systems, which is widely used in pharmaceutical, environmental protection, fuel cell and other fields. It is also the most important signal conducting molecule, second messenger and growth factor in Reactive Oxygen Species (ROS). The increase of intracellular H 2 O 2 level is closely related to cancer and neurodegenerative diseases. Therefore, the detection of H 2 O 2 is an important goal of clinical research. Herein, we synthesized molybdenum disulfide (MoS 2 ) with a lattice spacing of 0.62 nm using a simple method, maintaining the excellent characteristics of MoS 2 itself, and performing sensitive detection of H 2 O 2 . In this work, we use graphene oxide as the precursor, and use one-step hydrothermal method to synthesize three-dimensional molybdenum disulfide/reduced graphene oxide composite (MoS 2 /rGO). Graphene not only provides a support structure for the growth of MoS 2 , but also forms large number of pores in it. These channels greatly increase the specific surface area of the MoS 2 /rGO composite and provide a sufficient reaction environment for the reaction of H 2 O 2 on the composite. Its greatly improves the sensitivity of the MoS 2 /rGO enzyme-free sensor. We have calculated that the enzyme-free sensor composed of this electrode has a good linear dependence on the H 2 O 2 concentration in the range of 2 μM to 23.18 mM, and the detection limit is 0.19 μM. The enzyme-free sensor with simple preparation method is expected to be greatly developed in the clinical application of hydrogen peroxide sensor.