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 (AD) to detect the pesticide dodine (DD). Formation of a homoternary inclusion complex AD2@Q[10] in both aqueous solution and solid state was studied by means of 1H NMR spectroscopy and X-ray crystallography. Although AD can emit strong fluorescence in aqueous solution, the homoternary inclusion complex AD2@Q[10] does not exhibit any fluorescence. Upon the addition of the pesticide DD into the aqueous solution of AD2@Q[10], the AD molecules in the Q[10] cavity are displaced by the pesticide DD, and strong fluorescence recovers. The fluorescent probe system based on Q[10] and AD provided a wide determination of DD from 0 to 4.0 × 10-5 mol·L-1 with a low limit of detection of 1.827 × 10-6 mol·L-1. The guest-replacement fluorescence turn-on mechanism is also confirmed by 1H NMR spectroscopy. Further, the fluorescent probe can directly detect DD residues in real agricultural products, and obvious fluorescence signal was observed under UV irradiation.
Keyphrases
- fluorescent probe
- aqueous solution
- living cells
- single molecule
- risk assessment
- energy transfer
- high resolution
- heavy metals
- quantum dots
- magnetic resonance imaging
- human health
- mass spectrometry
- sensitive detection
- label free
- magnetic resonance
- solid phase extraction
- real time pcr
- contrast enhanced
- liquid chromatography