2.4.4 Quartz Crystal Microbalance Sensor for Organic Vapor Detection Based on Silica-Based Mesoporous Organic-Inorganic Hybrids

Silica-based mesoporous organic-inorganic hybrid materials have examined for their ability to detect vapors of small organic molecules with high sensitivity and selectivity. Mesoporous SBA-15 serves as an inorganic host with high specific surface area, facilitating gas adsorption, and thus leads to highly sensitive response; while the presence of organic functional groups contributes to the greatly improved specific sensing property. The behavior of the tailor-made sensing materials is characterized by quartz crystal microbalance (QCM) transducer. In this mini review, we report two high-performance QCM-based sensors in the application of nerve agent and formaldehyde detection. Hydrogen-bond acidic functional groups and amine were grafted onto SBA-15, respectively. Both of the sensors exhibited high sensitivity and selectivity to the vapor analyzed, with a ppb-level detection limit.