Construction　of　zeolite-type　frameworks　is　of　broad　interest　and　mainly　achieved　by　using　imidazolate　linkers.　Incorporation　of　multiple　linkers/functionalities　into　these　unique　types　of　frameworks　would　potentially　expand　their　application　scope.　Herein,　a　three-dimensional　(3D)　metal-organic　framework,　BUT-27,　with　a　unique　zeolite　A　structure　(LTA　topology)　was　synthesized　by　linker　exchange　via　single-crystal-to-single-crystal　transformation.　Addition　of　isophthalic　acid　linker　to　the　two-dimensional　double　layered　BUT-25　changed　the　whole　framework　to　a　3D　structure,　BUT-27,　containing　three　kinds　of　linkers.　The　strong　fluorescence　and　presence　of　free　O　and　N　atoms　in　the　framework　make　BUT-27　a　good　luminescent　sensor　for　the　detection　of　Fe3+　and　Cr2O72-　ions　with　high　selectivity　and　sensitivity,　i.e.　K-sv　=　1.1　x　10(4)　and　5.9　x　10(4),　and　LOD　(limit　of　detection)　of　0.19　and　0.26　mu　M,　respectively.　These　values　are　lower　than　the　minimum　values　specified　by　US-EPA　(United　States　Environmental　Protection　Agency)　indicating　its　high　potential　for　practical　applications.