An ICT phenanthro[9,10-d]imidazole-based fluorescence probe with aggregated characteristic for colorimetric detection of hypochlorous acid and its applications in water samples and living cells

Hypochlorous acid (HClO)/hypochlorite (ClO-) gets involved in many physiological and pathological processes. Although there is a lot of work that has been specifically reported in response to HClO, the ultrafast and colorimetric detection of HClO in the living body remains a challenge. Herein, we designed and synthesized a novel fluorescent probe PIP-AH based on the intramolecular charge transfer (ICT) mechanism, which showed an ultrarapid-response (within 5 s), the low detection limit (57.66 nmol center dot L-1) and the distinct colorimetric change (from green to blue) toward HClO titration in water solution. PIP-AH can make into the portable test papers for colorimetric determining HClO conveniently. Moreover, PIP-AH can be directly applied to detect HClO content in various actual water samples. Significantly, this probe was qualified for monitoring the variation of HClO levels in HeLa cells.