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 (NO₂), 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 (WO₃)/carbon nanotubes (CNTs)-based flexible sensor coupled with an Integrated Intelligent Sensing System (IISS) capable of on-site NO₂ detection, signal processing, and wireless mobile display. The optimized WO₃/CNTs sensor exhibits outstanding sensing performance, delivering a high response of 425.1% toward 1 ppm NO₂. Distinctively, by integrating the sensor into the IISS platform, real-time NO₂ 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 WO₃/CNTs sensor with a miniaturized IISS, offering a practical strategy for intelligent, wearable, and portable gas detection applications.