Stable In(III)-Based Metal–Organic Frameworks for Selective Detection of 4-Nitroaniline and Antibiotics in Water

Detection of harmful chemical reagents and pollutants is of great significance for protecting human health and environmental sustainability. In this work, a 3D metal–organic framework, named In-BTDI, has been synthesized, featuring a two-fold interpenetrated framework. In-BTDI shows intense luminescence with the emission peak at 502 nm and exhibits high structural and photo-stability in water and common organic solvents, which provides a good foundation to be unitized as a chemical sensor. In-BTDI can selectively and sensitively sense 4-nitroaniline (4-NA) and antibiotics by the fluorescence quenching effect not only in the organic solvent but also in water. It is noteworthy that the limits of detection (LOD) of 4-NA and antibiotics in water are 240 and 202 ppb, respectively, both reaching a ppb level, suggesting the good detection ability of trace analytes in water. The sensing mechanism was then discussed in detail.