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

Abstract

Hydrogen peroxide (H2O2) 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 H2O2 level is closely related to cancer and neurodegenerative diseases. Therefore, the detection of H2O2 is an important goal of clinical research. Herein, we synthesized molybdenum disulfide (MoS2) with a lattice spacing of 0.62 nm using a simple method, maintaining the excellent characteristics of MoS2 itself, and performing sensitive detection of H2O2. 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 (MoS2/rGO). Graphene not only provides a support structure for the growth of MoS2, but also forms large number of pores in it. These channels greatly increase the specific surface area of the MoS2/rGO composite and provide a sufficient reaction environment for the reaction of H2O2 on the composite. Its greatly improves the sensitivity of the MoS2/rGO enzyme-free sensor. We have calculated that the enzyme-free sensor composed of this electrode has a good linear dependence on the H2O2 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.