β-Cyclodextrin functionalized molybdenum disulfide quantum dots as nanoprobe for sensitive fluorescent detection of parathion-methyl.

Through modifying molybdenum disulfide quantum dots (MoS QDs) with 3-aminophenyl boronic acid and functionalizing further with hydropropyl-β-cyclodextrin (β-CD), a novel nanoprobe based on β-CD functionalized MoS QDs (β-CD-MoS QDs) was developed for the fluorescent detection of parathion-methyl (MP). β-CD-MoS QDs was characterized with various technologies including transmission electron microscopy, X-ray photoelectron spectroscopy, fluorescence and UV-Vis absorption spectra. As for MP detection, MP was hydrolyzed to p-nitrophenol (p-NP) under the alkaline conditions, and p-NP can enter into the β-CD cavity due to the host-guest recognition capability of β-CD, which then results the fluorescence quenching of nanoprobe. Based on this principle, an enzyme-free fluorescence sensing platform were constructed for MP. Under the optimal conditions, β-CD-MoS QDs nanoprobe exhibits wide detection scope (0.01-18.0 ppm) and low detection limits (3.3 ppb) for MP detection. In addition, the nanoprobe has excellent selectivity for MP, and it can be applied to detect MP in real samples.