Electrochemical detection of methotrexate in serum sample based on the modified acetylene black sensor

A novel acetylene black (AB) sensor modified with stearyltrimethylammoniumbromide (STAB) was fabricated and applied to the determination of methotrexate (MTX) in serum. For the strong adsorption of STAB and the high catalytic capacity of AB, the prepared sensor performed better adsorption and electrochemical catalysis capacity compared with acetylene black paste electrode (ABPE). Several factors affecting the performance of the sensor, such as the construction of the sensor and the parameters affect the electrochemical catalysis were optimized carefully on sequences in this study. The prepared sensor showed favorable performance in the determination of MTX with the linear range of 0.005 mu M to 7.0 mu M and the detection limit of 3.07 nM. Furthermore, the fabricated sensor exhibited good stability and repeatability, which was of importance in the electrochemical detection. Finally, the established electrode was employed in the detection of MTX in real sample of serum, which demonstrated the reliable and accurate of the prepared method. It is obvious that the prepared sensor existed great potential in the determination of MTX, which could provide a new approach for the fast and low-coat detection for MTX.