Fluorescence spectroscopy: detection and sensing of SO₂ and H₂S using MOFs and other emerging porous materials

In this tutorial review we introduce the basic concepts on fluorescence spectroscopy as an analytical technique to detect and sense sulphur dioxide (SO₂) and hydrogen sulphide (H₂S), specifically, by using metal-organic frameworks (MOFs) and emerging porous materials i.e., covalent organic frameworks (COFs) and porous organic cages (POCs) as fluorescent probes. Following a logical order, we present the basic concepts of fluorescence spectroscopy, origin of fluorescence in MOFs, a concise description of emerging applications of fluorescent MOFs, specific H₂S and SO₂ interactions with MOFs structures, and selected edge of science examples of MOFs, COFs and POCs as probes with special emphasis on the relationship between materials' chemical structure and fluorescence response. Finally, after each example, we describe the strategy employed to detect the specific analyte.