Turn-on luminescence detection of biogenic amine with an Eu(III) tetrahedron cage

Selective and sensitive detection of volatile biogenic amines (BAs) have been attracting considerable interests because it can be utilized as freshness markers of food. Herein, an Eu(III) tetrahedron cage (Eu4L24) constructed from a tris-β-diketone is exploited as luminescence sensor for BAs. The spin-coated film of Eu4L24 presents turn-on emissive, and rapidly reversible responses to some volatile BAs with millisecond response time. The turn-on luminescence response to BAs attributes to nucleophilic interaction of amine group to carbonyl carbon atom of trifluoroacetyl in ligand. While the large cavity and rhombus opening lying on the edges of tetrahedron ensure excellent permeability of the film to BAs, which is responsible for the rapidly response times. Furthermore, vapor phase detection of the BAs was extended to practical application for monitoring fish spoilage. The experimental results affirm the practicability of cage as sensing materials for monitoring food spoilage.