Electrochemical sensor based on Ti 3 C 2 membrane doped with UIO-66-NH 2 for dopamine.

A Ti 3 C 2 membrane was prepared by doping UIO-66-NH 2 with Ti 3 C 2 through hydrogen bonds. When the doping mass ratio of Ti 3 C 2 and UIO-66-NH 2 was 6:1, the electrochemical performance was optimal. Characterization was done by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and electrochemical impedance spectroscopy (EIS) which exhibited hierarchical cave-like physiognomy, large specific area, outstanding electronic conductive network, and excellent film-forming property. Moreover, the Ti 3 C 2 film was analyzed via atomic force microscopy (AFM), which displayed good mechanical properties and rough surface morphology. The fabricated Ti 3 C 2 membrane/GCE sensor was applied to the detection of dopamine (working potential of + 0.264 V vs. Ag/AgCl) with LOD of 0.81 fM and a sensitivity of 14.72 µA fM -1  cm -2 . It was demonstrated that the Ti 3 C 2 membrane can be used to construct nonenzymatic sensors with excellent performance. The fabricated sensor has high selectivity and stability and has good practicability with recoveries of 101.2-103.5% and a relative standard deviation (RSD) of 1.2-2.4%.