In　consideration　of　the　strong　oxidizing　power　of　hypochlorite　(ClO−),　which　could　cleave　C[dbnd]N　moiety,　a　cyclometalated　iridium　(III)　complex　(Ir-Ts)　modified　hydrazide　group　as　the　response　unit　was　synthesized　to　sensitively　and　selectively　detect　ClO−　under　neutral　condition.　Upon　addition　of　ClO−,　a　21-fold　emission　enhancement　at　574　nm　was　observed　and　phosphorescent　product　was　formed　due　to　the　cleavage　of　C[dbnd]N　moiety.　The　probe　Ir-Ts　displayed　rapid　response　(<15　s)　and　high　selectivity　toward　ClO−　with　a　low　detection　limit　of　86　nM.　More　importantly,　bioimaging　of　ClO−　was　further　studied　in　living　cells.　©　2020　Elsevier　Inc.