Highly efficient and cost-effective polyaniline-based ammonia sensor on the biodegradable paper substrate at room temperature.

A highly efficient, flexible and cost-effective ammonia (NH 3) gas sensor is developed on a biodegradable paper substrate. The polyaniline (PANI) film as an active sensing material was deposited by a simple in-situ polymerization method and optimized for NH 3 detection. The PANI film was investigated using X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) for structural and morphological properties. The sensor was tested for its efficiency to detect the NH 3 gas over the concentration range of 12–1000 ppm at room temperature. The sensor showed excellent repeatability, stability and selectivity towards NH 3 detection. At concentrations of 12 ppm (lower level), 200 ppm (intermediate level), and 1000 ppm (higher level), the sensor exhibited effective response values of 3.60, 6.85, and 9.33, respectively. The sensor exhibited a quick response time of 30–9 s when subjected to 12–1000 ppm of NH 3. The sensor can detect ammonia gas in real-time, which makes it useful for identifying rapid changes in NH 3 concentration. The sensor response was reduced by 5.5% towards 200 ppm NH 3 despite a significant variation in relative humidity from 20% to 80%. Based on these results, our flexible PANI sensor is a viable option for efficient and cost-effective on-site NH 3 detection. [Display omitted] • We fabricated a room temperature operational, highly sensitive and selective polyaniline based ammonia gas sensor. • The sensor is fabricated over the bio-degradable paper substrate which makes it flexible and cost-effective. • The sensor exhibited a linear response with increasing NH 3 concentration along with excellent repeatability and stability. • The effect of relative humidity on the sensor response has been thoroughly investigated. [ABSTRACT FROM AUTHOR]