Electrochemical determination of epinephrine based on Ti3C2Tx MXene-reduced graphene oxide/ITO electrode

Abstract EP is an important natural catecholamine neurotransmitter in the central nervous system, and the change of EP concentration will lead to many diseases. Therefore, rapid and sensitive detection of EP is of great significance for clinical research. The Ti3C2Tx MXene dispersion obtained by in-situ HF etching Ti3AlC2 was mixed with graphene oxide (GO) dispersion synthesized by the modified Hummers method. After freeze drying and heat-treatment, the reduced graphene oxide/Ti3C2Tx MXene (GMA) was obtained and then the GMA was moved onto indium tin oxide (ITO) as the GMA/ITO working electrode for electrochemical detection of epinephrine (EP). The results are as follows: Ti3C2Tx MXene with a diameter of approximately 150 nm is uniformly distributed on the surface of the 3D graphene. The three-dimensional structure of GMA facilitates the entry of bioactive molecules and increases the contact area. GMA/ITO has a high sensitivity for the determination of EP 3.74 μA·μM−1·cm−2. Moreover, the electrode shows a very low detection limit, well repeatability and stability, and it can detect the EP content in real urine samples.