Melanoma,　with　poor　prognosis　and　highly　metastatic　spread,　is　the　most　deadly　skin　cancer,　but　the　monitoring　and　diagnosis　of　melanoma　is　still　a　challenging.　The　rate-limiting　enzyme　tyrosinase　is　crucial　for　controlling　melanin　production,　and　is　a　well-known　biomarker　closely　associated　with　the　level　of　malignancy.　However,　effective　probes　for　detecting　tyrosinase　in　living　cells　are　currently　lacking.　This　paper　describes　the　design,　synthesis　and　characterization　of　F2,　a　high　sensitive　type　of　＂turn-on＂　fluorescent　probe　for　imaging　living　melanoma　cells.　F2　could　be　activated　by　tyrosinase-catalyzed　oxidation　followed　by　hydrolysis　of　a　urea　linkage.　The　results　demonstrate　that　F2　displays　cyan　fluorescence　when　activated　by　tyrosinase,　and　has　sufficient　sensitivity　and　selectivity　to　detect　tyrosinase　in　aqueous　solution　and　in　living　cells.　F2　has　potential　for　the　noninvasive　real-time　diagnosis　and　tracking　of　melanoma.　(C)　2016　Elsevier　B.V.　All　rights　reserved.