In situ enrichment amplification strategy enabling highly sensitive formaldehyde gas sensor

Rapid detection of hazardous trace gas is critical to protect humans from health threats. The current gas sensors, however, suffer from insufficient sensitivity and selectivity, which limits their use in the application of real-time monitoring for low concentration gas. Herein, a versatile “in situ enrichment amplification” (IEA) strategy is proposed, aiming to integrate the in situ formed adsorption-functional material for target gas enrichment and the backbone sensor-functional material for gas response. The IEA-based gas sensors exhibit high sensitivity and selectivity toward the detection of HCHO gas. The calculated detection limit of the IEA sensor to HCHO gas is 63 ppb, much lower than that of the conventional HCHO sensor (183 ppb). Furthermore, a wireless cloud HCHO detection system is developed to achieve sustainable remote monitoring of the HCHO gas. Application of this IEA strategy to other metal oxide sensing materials generates similarly successful results. A feasible “in situ enrichment amplification” (IEA) strategy is proposed, aiming to integrate the adsorption-functional material for target gas enrichment and the sensor-functional material for gas sensing reaction. As a result, the IEA-based gas sensor delivers high sensitivity with a response value of 23.7 towards 100 ppm HCHO, low detection limits (63 ppb), and sound selectivity. Furthermore, a wireless cloud HCHO detection system is developed to achieve sustainable remote monitoring of the HCHO gas. [Display omitted] •An “in situ enrichment amplification” gas sensing strategy was proposed, which integrated the adsorption-functional material for gas enrichment and the sensor-functional material for gas response.•The IEA-based gas sensors deliver high sensitivity and low detection limits (63 ppb) to HCHO gas.•The wireless cloud HCHO detection (CHD) system based on IEA-based gas sensor demonstrates sustainable monitoring and early warning of HCHO gas.