Integrated intelligent sensing system with WO3/CNTs sensor for on-site gas detection

Gas sensors integrated with intelligent systems are of great importance for real-time environmental monitoring and personal exposure assessment. In particular, nitrogen dioxide (NO 2 ), a toxic byproduct of combustion and industrial processes, poses severe risks to human health even at trace levels, highlighting the urgent need for sensitive and portable monitoring technologies. Here, we present a tungsten trioxide (WO 3 )/carbon nanotubes (CNTs)-based flexible sensor coupled with an Integrated Intelligent Sensing System (IISS) capable of on-site NO 2 detection, signal processing, and wireless mobile display. The optimized WO 3 /CNTs sensor exhibits outstanding sensing performance, delivering a high response of 425.1 % toward 1 ppm NO 2 . Distinctively, by integrating the sensor into the IISS platform, real-time NO 2 concentrations can be acquired, processed, and displayed on a mobile device, enabling direct and user-friendly exposure monitoring. These results highlight the novelty of combining a high-performance WO 3 /CNTs sensor with a miniaturized IISS, offering a practical strategy for intelligent, wearable, and portable gas detection applications.