Detecting Pesticide Dodine by Displacement of Fluorescent Acridine from Cucurbit[10]uril Macrocycle.

According to a simple guest-replacement fluorescence turn-on mechanism, we constructed a fluorescent probe system based on cucurbit[10]uril (Q[10]) and protonated acridine () to detect the pesticide dodine (). Formation of a homoternary inclusion complex @Q[10] in both aqueous solution and solid state was studied by means of H NMR spectroscopy and X-ray crystallography. Although can emit strong fluorescence in aqueous solution, the homoternary inclusion complex @Q[10] does not exhibit any fluorescence. Upon the addition of the pesticide into the aqueous solution of @Q[10], the molecules in the Q[10] cavity are displaced by the pesticide , and strong fluorescence recovers. The fluorescent probe system based on Q[10] and provided a wide determination of from 0 to 4.0 × 10 mol·L with a low limit of detection of 1.827 × 10 mol·L. The guest-replacement fluorescence turn-on mechanism is also confirmed by H NMR spectroscopy. Further, the fluorescent probe can directly detect residues in real agricultural products, and obvious fluorescence signal was observed under UV irradiation.