Graphene/Polyaniline Film Optical Fiber Ammonia Gas Sensor With Excellent Sensing Performance

Abstract

The possibility to improve the detection index of the optical ammonia gas sensors on the basis of the graphene/polyaniline (graphene/PANI) coated Mach–Zehnder interferometric optical fiber structure with etched thinned core fiber(e-TCF) is investigated. Based on the analysis of the output wavelength, a significant increase in sensitivity and stability of the ammonia sensors is achieved by using TCF. Experimental results show that its sensitivity is -27.8 pm/ppm, the response time is 32 s, dip wavelength error is lower than ±0.02 nm, and the dip intensity error is lower than ±0.002 dB in the stability test. This research illustrates that the proposed sensor has numerous advantages, including small size, strong anti-electromagnetic interference, and excellent repeatability characteristics. Furthermore, it can be applied in biomedical detection applications as it can improve the detection resolution of ammonia concentration at room temperature.