Ultrafast ppb-Level Detection of Nitro-Furan Based Antibiotics in Aqueous Medium by an Oxadiazole-Grafted Luminescent Sensor.

This work is primarily focused on the utilization of an oxadiazole grafted 2D luminescent metal-organic framework, {[Zn(4-tpom)(oxdz)]⋅4HO} (1), in the detection of trace amounts of nitrofuran-based antibiotics such as nitrofurantoin (NFT) and nitrofurazone (NFZ) in aqueous medium. The π-electron rich moieties and the H-bond accepting sites in the dual linkers (4-tpom and oxdz) enable the framework to interact efficiently with NFT and NFZ exhibiting a turn-off fluorescence response with the respective K (6.55×10 M and 4×10 M) and LOD (89 ppb and 78 ppb) values. Furthermore, the efficiency of 1 in sensing commercially sold antibiotic tablet, Martifur-100 (contains nitrofurantoin as an active ingredient), is demonstrated as an example with an LOD value of 277 ppb. Its multicycle reusability and the ultrafast response toward these antibiotics are also reported. The nature of quenching of 1 by NFT and NFZ has been investigated with experimental and theoretical considerations.