A novel mitochondria-targeted phosphorescence probe for hypochlorite ions detection in living cells

Monitoring hypochlorite anion (ClO−) in living cells is particularly meaningful and valuable, because over-exposure of the ClO− may cause a potential health hazard towards animals and humans. Considering the special structure and properties of the gemini surfactant, a novel amphiphilic gemini-iridium complex Ir[(ppy-iso)2(bpy-tma2Br2)] (Ir-iso) with isoniazide as a recognition site for ClO− was designed. The Ir-iso possessed an excellent water-solubility as well as a strong ClO− binding capacity, as revealed from the rapid response of emission signal towards ClO−. It was worth noting that such probe had a highly-specific selectivity with a low detection limit (20.5 nM) and was suitable in physiological environment. The cell viability assay, cell imaging, and co-location studies further proved that the Ir-iso had little cytotoxicity and was specifically localized in the mitochondria of breast cancer cells, being a promising candidate of chemo-sensor to detect the endogenous ClO− in living cells. [Display omitted] •A novel Ir-iso sensor with isoniazide as a recognition site for the detection of ClO− is presented.•The sensor exhibits a significantly improved water-solubility and a strong ClO− binding capacity.•The sensor is capable of detecting 20.5 nM of ClO− in physiological environment with a highly specific selectivity.•Little cytotoxicity and mitochondria-targeted phosphorescence probe for the detection of endogenous ClO−.