An In-ZnO nanosheet–modified carbon nanotube–polyimide film sensor for catechol detection

We report the fabrication of a catechol (CC) sensor based on an In-modified ZnO/carbon nanotube–polyimide (In-ZnO/PI–CNT) film by using a simple electrochemical method. The decoration of In nanoparticles and control of the size and morphology of In nanostructures provide a great opportunity to improve the catalytic activity of ZnO nanosheets. In nanoparticles supported on the ZnO nanosheets exhibit relatively large surface areas and can enhance the electron transfer. An In-ZnO/PI–CNT film is more active for the catalysis of CC than the ZnO/PI–CNT film and the In(3.79%)-ZnO/PI–CNT film shows the best catalytic activity. The In(3.79%)-ZnO/PI–CNT film sensor exhibits a wide linear range, good long-term stability and reproducibility, and performs well for detection of CC in real water samples. The In(3.79%)-ZnO/PI–CNT film holds great potential for the fabrication of efficient sensors.