Direct and sensitive detection of sulfide ions based on one-step synthesis of ionic liquid functionalized fluorescent carbon nanoribbons.

Despite widely reported fluorescence sensors for cations, direct detection of anions is nevertheless still rare. In this work, ionic liquid-functionalized fluorescent carbon nanoribbons (IL-CNRs) are one-step synthesized and serve as the fluorescent probes for direct and sensitive detection of sulfide ions (S 2- ). The IL-CNRs are synthesized based on electrochemical exfoliation of graphite rods in a water-IL biphasic system. The as-prepared IL-CNRs exhibit uniform structure, high crystallinity, strong blue fluorescence (absolute photoluminescence quantum yield of 11.4%), and unique selectivity towards S 2- . Based on the fluorescence quenching of IL-CNRs by S 2- , a fluorescence sensor is developed for direct, rapid and sensitive detection of S 2- in the range of 100 nM to 1 μM and 1-300 μM with a low detection limit (LOD, 85 nM). Moreover, detection of S 2- in a real sample (tap water) is also demonstrated.