Histamine　is　a　kind　of　biogenic　amine　released　in　spoiled　food,　which　can　serve　as　a　key　indicator　for　assessing　the　freshness　of　seafood.　It　is　important　to　develop　some　efficient　methods　for　histamine　detection.　In　this　work,　a　dual-emission　europium-metal-organic　framework　(Eu-MOF)　was　designed　and　applied　to　design　a　ratiometric　fluorescence　sensing　strategy　for　histamine　detection.　The　MOF　was　synthesized　in　one　step　using　two　ligands:　5-boronoisophthalic　acid　(5-BOP)　and　2-hydroxyterephthalic　acid　(BDC-OH).　Eu3+　was　sensitized　by　5-BOP　through　the　antenna　effect　and　exhibited　red　emission　at　618　nm,　while　the　BDC-OH　exhibited　bright　blue　emission　at　434　nm.　The　MOF　displayed　dual-emission　responses　to　histamine,　characterized　by　an　increase　in　434　nm　and　a　concomitant　decrease　at　618　nm,　so　the　ratio　of　I618/I434　decreased　with　a　pronounced　fluorescence　color　shift　from　purple　to　blue.　I618/I434　exhibited　a　linear　range　with　histamine　from　0　to　200　mg/L　with　a　detection　limit　of　0.17　mg/L　(LOD　=　3σ/KSV).　The　synthesized　Eu-BOP/BDC-OH　was　integrated　with　carrageenan　to　fabricate　a　hydrogel　composite　film　for　portable　detection　of　histamine,　and　the　changing　of　color　can　be　utilized　for　semiquantitative　freshness　detection.　The　proposed　method　provided　a　reliable　and　efficient　portable　strategy　for　histamine　detection　in　seafood.　©　2025　American　Chemical　Society.