Self-assembled deposition of polyaniline/cobalt porphyrin based on flexible PET to improve sensing of room-temperature NH3 sensor

The development of efficient and flexible ammonia (NH3) detection equipment for monitoring air quality remains a great challenge. Herein, a room-temperature polyaniline/cobalt porphyrin (PANI/CoTPP, PCT) NH3 sensor based on an ITO-PET substrate was prepared by a one-step self-assembled electrodeposition method. Although the aggregated CoTPP particles reduced the conductivity of PANI molecular chains, they could help to capture NH3 molecules. Thus, the fabricated PCT flexible sensor showed superior sensitivity with a theoretical detection limit of ∼ 0.83 ppm NH3, high selectivity, and excellent sensing stability. The NH3 sensing mechanism of the PCT sensor was further investigated with the aid of density functional theory (DFT) calculations. Hence, the combination of conductive polymer with porphyrin-based sensitive material in the form of a flexible sensor is expected to be used as a simple device for tracing NH3 in the environment.