Novel water-soluble fluorescent probe for rapidly detecting SO2 derivatives

In this paper, two novel benzothiazole derivatives EtSN and OAcSN with a D–π–A configuration were developed as fluorescent probes for the detection of HSO3−. Compared with OAcSN, probe EtSN, bearing ester group, displayed a lower detection limit and faster response time. Upon treatment with HSO3−, EtSN and OAcSN displayed noticeable color change from yellow (EtSN)/red (OAcSN) to coreless, respectively. Competitive experiments indicated that EtSN and OAcSN had higher fluorescence selectivity towards HSO3− than other analytes. The sensing mechanism was further illustrated by 1H NMR and TD-DFT.