Easy networking enhanced quantum wires-based fiber probe for highly sensitive NH3 gas detection at room temperature

The detection of toxic ammonia (NH₃) gas across multiple channels at room temperature, especially under complex conditions, consistently presents a significant challenge. In this paper, a plasmonic Pt-doped SnO₂ enhanced quantum wires NH₃ gas sensor is constructed on a 125-µm communication fiber with easy networking. To enhance usability in confined areas, the sensor features a compact plug-in fiber probe design. The plasmonic Pt-doped SnO₂ enhanced quantum wires coating boosts the interaction between NH₃ gas molecules and oxygen adsorbed on the wires' surface, modulating the plasmonic optic signal. We present and compare two optical modulation methods-wavelength and intensity-for our NH₃ gas probe. Our sensor achieves an impressive intensity sensitivity of −10.45 a.u./ppm at room temperature with a rapid response time of 3.8 s. Furthermore, intensity modulation offers an exceptionally low detection limit of 287 ppb, with minimal susceptibility to temperature and humidity variations. The proposed fiber NH₃ gas probe exhibits commendable specificity, repeatability, stability, and cost-effectiveness, along with flexibility in light source and receiver choices, making it ideal for NH₃ gas detection applications.