Two　new　bichromophoric　ruthenium(II)　complexes,　[Ru(bpy)　2(bpy-CM)](PF　6)　2　and　[Ru(bpy)　2(bpy-CM343)](PF　6)　2　(bpy=2,2＇-bipyridine,　CM=coumarin)　with　appended　coumarin　ligands　have　been　designed　and　synthesized.　The　energy-transfer-based　sensing　of　esterase　by　the　complexes　has　been　studied　by　using　UV/Vis　and　luminescence　spectroscopic　methods.　The　cytotoxicity　and　the　cellular　uptake　of　one　of　the　complexes　have　also　been　investigated.　Woodruff-not　only　tasty!　Two　new　bichromophoric　ruthenium(II)　complexes　with　appended　coumarin　ligands　have　been　synthesized.　The　energy-transfer-based　sensing　of　esterase　by　the　complexes　was　studied　by　using　UV/Vis　and　luminescence　spectroscopy.　The　Ru　II　complex　containing　a　coumarin　343　derivative　was　found　to　exhibit　only　a　slight　cytotoxicity　towards　HepG2　cells,　and　it　was　easily　taken　up　in　the　living　cells　to　show　evident　response　to　the　esterase　(see　figure).　Copyright　©　2012　WILEY-VCH　Verlag　GmbH　&　Co.　KGaA,　Weinheim.