A fluorescent sp2c-covalent organic polymer with an aggregation-induced emission unit to suppress aggregation-induced quenching for sensing furazolidone†
Abstract
Furazolidone (FZD) is a nitrofuran antibiotic that has an inhibitory effect on a variety of Gram-negative and positive bacteria. However, excessive use of FZD can produce major adverse responses and irreversible harm to the central nervous system, so it is necessary to develop a simple, rapid, highly selective and sensitive method for the detection of FZD. Here, a sp2c-covalent organic polymer (COPPDAN-BTT) containing benzotrithiophene was synthesized for fluorescence sensing FZD. The benzotrithiophene in the BTT monomer is a typical aggregation-induced quenching (ACQ) fluorophore, and the cyanide diphenylethylene unit has certain aggregation-induced emission (AIE) properties. The connection of the ACQ fluorophore and the AIE fluorophore can fully improve the ACQ degree of COPPDAN-BTT. Under excitation at 370 nm, COPPDAN-BTT exhibits green fluorescence at 500 nm. Based on the internal filtering effect, COPPDAN-BTT was used for FZD detection. The I0/I showed a good linear relationship with the concentration of FZD in the range of 0.034–20 μg mL−1 (0.149–88.9 μM), and the detection limit was as low as 0.011 μg mL−1 (0.049 μM). Based on the AIE properties of COPPDAN-BTT, a fluorescent test strip was prepared for visual detection of FZD. This work provides a simple yet effective method for detection of FZD and improving the fluorescence of COPs.