Pyridine-substituted cyanostilbene mcrocycle: A “turn-on” fluorescence sensor for pesticide bromoxynil octanoate

Pesticide bromoxynil octanoate is widely used in agriculture but possesses the potential toxicity to both animals and humans. The development of facile and on-site detection method for bromoxynil octanoate is extremely expected. In this work, the first example of fluorescent sensor for on-site examining bromoxynil octanoate in aqueous media was reported based on a pyridine-substituted cyanostilbene macrocycle (PSCM). This fluorescent sensor exhibited strong “turn-on” orange fluorescence on sensing bromoxynil octanoate with high selectivity and sensitivity among a wide range of ions and pesticides. The limitation of detection is 2.1 × 10−8 M. The study on binding mechanism suggested that bromoxynil octanoate is located in the cavity of PSCM based on π-π and hydrophobic interactions. The application experiments indicated that this fluorescent sensor has the excellent sensing behavior on test papers, four real agriculture samples and simulated water samples, implying the good application potential on facile, simple and on-site detecting bromoxynil octanoate in real environments.