A corrole-based fluorescent probe for detection of sulfur ion and its application in living cells

A dual signaling probe DPC-O-NBD formed through the conjugation of 5,15-bis(phenyl)-10-(4-hydroxylphenyl)-corrole (DPC-OH) with 4-chloro-7-nitrobe-nzo-2-oxa-1,3-diazole (NBD-Cl) is explored to detect sulfur ion (S2−). The key design principle is based on the nucleophilicity of S2−, which can be used to cleave the bridging ether bond in the probe to obtain both fluorogenic and chromogenic signaling behaviors. Importantly, the probe DPC-O-NBD not only showed a high sensitivity (LOD: 48 nM) and selectivity over other interfering species, but also exhibited a rapid response (∼18 s) towards S2−. Furthermore, DPC-O-NBD can also be used to detect S2− in both water and live cells, providing a potentially powerful approach for probing S2− chemistry in biological systems.