“…However, these often require complicated procedures and intricate precursors, especially organic ones, for preparing certain FL probes for sensing particular targets and, in many cases, the obtained probes still suffer from low solubility in aqueous phase, poor biocompatibility and photobleaching during the sensing process. [ 8,27,28 ] In contrast, inorganic quantum dots (QDs) have unique optical properties including high quantum yields, photostability and biocompatibility, and broad absorption spectra with narrow emission spectra, thereby driving tremendous attentions as the probes for sensing diverse organic and inorganic analytes including S 2− and/or H 2 S. [ 29–31 ] During recent years, QD‐coated paper has attracted increasing attentions as new analytical device that benefited from its simplicity, rapidness, cost–effectiveness, and visual output. [ 32,33 ] However, the interference from liquid‐phase sample matrices should not be ignored when using paper‐based sensors, especially in the analysis of real samples.…”