Free‐standing and Flexible MoS 2 /rGO Paper Electrode for Amperometric Detection of Folic Acid

The development of flexible electrodes is of considerable current interest because of the increasing demand for modern electronics, portable medical products, and compact devices. We report a new type of flexible electrochemical sensor fabricated by integrating graphene and MoS 2 nanosheets. A highly flexible and free‐standing conductive MoS 2 nanosheets/reduced graphene oxide (MoS 2 /rGO) paper was prepared by a two‐step process: vacuum filtration and chemical reduction treatment. The MoS 2 /graphene oxide (MoS 2 /GO) paper obtained by a simple filtration method was transformed into MoS 2 /rGO paper after a chemical reduction process. The obtained MoS 2 /rGO paper was characterized by scanning electron microscopy, X‐ray diffraction spectroscopy, X‐ray photoelectron spectroscopy, Raman spectroscopy, electrochemical impedance spectroscopy. The electrochemical behavior of folic acid (FA) on MoS 2 /rGO paper electrode was investigated by cyclic voltammetry and amperometry. Electrochemical experiments indicated that flexible MoS 2 /rGO composite paper electrode exhibited excellent electrocatalytic activity toward the FA, which can be attributed to excellent electrical conductivity and high specific surface area of the MoS 2 /rGO paper. The resulting biosensor showed highly sensitive amperometric response to FA with a wide linear range.