A Novel Formaldehyde Gas Sensor Based on Ag-LaFeO₃ Using Molecular Imprinting Technique

Abstract

A novel gas sensor for the determination of formaldehyde was developed based on molecular imprinting technique (MIT). MIT was for the first time used to recognize small organic molecule by our group. The molecular imprinting nanoparticles (MINs) with a small dimension which possess extremely high surface-to-volume ratio were synthesized using imprinting polymerization with formaldehyde as template and Ag-LaFeO3 as substrate material. The structure of the MINs is orthogonal perovskite. And then the MINs were printed onto an alumina tube. Subsequently, a high selectivity molecular imprinting gas sensor for detection of formaldehyde was achieved. At 86°C, the response to 0.5 ppm formaldehyde based on the sensor is 16, and the response is lower than 2 for the other test gases. The response time and recovery time are 55 s and 40 s, respectively.

Advancements in lanthanide-based perovskite oxide semiconductors for gas sensing applications: a focus on doping effects and development

“…Thus, MINs improve the selectivity of the sensors towards lowconcentration formaldehyde effectively. 74,75 For metal oxide semiconductor devices, the distinctive electrical properties (electron mobility and carrier lifetime) are critical elements that directly affect the device's functionality and application. The responsiveness and operating temperature of the gas sensor are somewhat inuenced by the electron mobility of the metal oxide semiconductor.…”

“…Thus, MINs improve the selectivity of the sensors towards low-concentration formaldehyde effectively. 74,75…”