Development of a selective reaction-based turn-on fluorosensor and biomarker for hypochlorite ions in aqueous media†
A new organic moiety, 2-benzotriazol-2-yl-6-[1,3]dithiolan-2-yl-4-ethyl-phenol (LH), was designed, synthesized and structurally characterized as an excellent sensor for hypochlorite ions in aqueous media at pH 7.4. The non-fluorescent LH showed outstanding ICT-based switch-on fluorescence for hypochlorite ions at a concentration as low as 12.58 nM with great sensitivity based on the hypochlorite ion-selective controlled oxidation cleavage reaction of its thioacetal linkage, which was supported by 1HNMR and 13CNMR titrations. The observed spectroscopic changes were validated by theoretical (DFT) calculations. The non-cytotoxic probe has potential application for hypochlorite (ClO−) ion imaging in living cells, which was revealed by imaging human breast cancer (MCF-7) and murine macrophage (J774A1) cell lines via fluorescence microscopy.