A PDA functionalized CNT/PANI self-powered sensing system for meat spoilage biomarker NH3 monitoring

To achieve a real-time monitoring of ammonia (NH 3 ) from meat spoilage, a self-powered wireless sensing system has been fabricated, including a novel NH 3 sensor, a bluetooth module and a home-made sphere triboelectric nanogenerator (TENG). The system is self-powered and wireless, which meets up well with the demand of meat freshness monitoring, especially for the long-distance transportation. The sensor of the system is based on the polydopamine (PDA)- functionalized carbon nanotube (CNT) coated with polyaniline (PANI), showing superb sensing performance to NH 3 from 0.5 to 20 ppm, with a limit of detection of 38 ppb. And the sensor has presented outstanding anti-interference ability towards common interfering gases and exhibited outstanding stability during the experiments. The sensing system has advantages of portability, sustainability and non-pollution, making it a promising candidate of real-time monitoring application.