Fluorescent Ionic Liquid Membranes Based on Coumarin for the Real-Time and Visual Detection of Gaseous SO₂

Abstract

Presented here is a novel design strategy that utilizes anion-functionalized ionic liquids (ILs) to achieve visual and real-time detection of gaseous SO2. A coumarin fluorophore was innovatively covalently linked onto an IL and exhibited fluorescent signal response for SO2 due to strong chemical interactions. The sensor consisting of this IL displayed high sensitivity and selectivity, even toward trace amounts of SO2 (<0.2 ppm). Furthermore, this sensor overcame weak anti-interference ability and water-sensitivity issues. Benefiting from its excellent solubility, the sensor could be assembled into a simple and portable membrane device and exhibited excellent reusability (>12 times). The reported membrane sensor may be used as a next-generation gas sensor with superior SO2-response performance, enabling a wide application for monitoring harmful gases.

An in situ, reversible fluorescent paper sensor for selective detection of ambient CO2

“…In living environments, the concentrations of NO 2 and SO 2 are minimal (o1-2 ppm). 32,47 Thus, the selective detection of ambient CO 2 over SO 2 and NO 2 can be realized. Compared with other reported sensors, this CO 2 paper sensor possesses excellent analytical capability for the selective detection of CO 2 .…”

“…29 They can offer inherent advantages in terms of facile synthesis, low cost, and easy tunability, making them promising in the field of optical sensing. 30 IL-based fluorescent sensors were reported to detect H 2 O 2 , 31 SO 2 , 32 and halogen anions. 33 Combined with polymer membranes, ILs can serve as solid-state sensors for in situ , simple, and handy detection.…”