A cerium-based metal-organic tetrahedron has been developed as a highly selective and sensitive fluorescence sensor for the recognition of 4-amino-2,6-dinitrotoluene (4-ADNT). The redox-active tetrahedron could encapsulate 4-ADNT through weak interaction and spatial stereoselectivity, resulting in an enhanced fluorescence. The tetrahedral sensor Ce-ZPS is capable of realizing fluorescent sensing in urine and in cells and thus has the potential to detect 4-ADNT in organisms.