Hydrazine　(N2H4)　has　been　classified　as　an　environmental　contaminant　arid　human　carcinogen　owing　to　its　high　toxicity.　Exposed　to　high　concentration　of　hydrazine　can　cause　irreversible　damage　to　human　bodies.　Hence,　it　is　significant　to　explore　an　effective　analytical　method　to　selectively　recognize　and　detect　it.　In　this　work,　an　intramolecular　charge　transfer　(ICT)　based　probe　1　was　designed　and　synthesized　by　condensation　of　V-shaped　bis-coumarin　and　4-bromobutyric　acid.　The　V-shaped　bis-coumarin　with　pi-expanded　system　endowed　the　probe　1　larger　stokes　shift　and　superior　tolerance　to　photobleaching.　This　＂turn-on＂　probe　exhibited　a　high　selectivity　towards　hydrazine　over　other　common　ions　and　amine-containing　species　with　a　distinct　fluorescent　enhancement　at　555　nm.　It　could　rapidly　detect　hydrazine　over　a　wide　pH　range　and　the　detection　limit　was　as　low　as　4.2　ppb.　The　large　shift　of　absorption　spectrum　enabled　it　to　detect　hydrazine　in　real　water　samples　and　gas-state　hydrazine　by　＂naked-eyes＂.　(C)　2020　Elsevier　Ltd.　All　rights　reserved.