Phosphorescent Inner Filter Effect-based Sensing System for Determination of β-Glucuronidase Using Manganese-doped Zinc Sulfide Quantum Dots / 分析化学

The key to maximize the sensitivity of inner filter effect ( IFE)-based assay is to enlarge the overlap between the absorption spectra of the absorber and the excitation or emission spectra of the fluorophore. In this work, Mn-doped ZnS quantum dots ( QDs) were chosen for IFE-based detection of β-glucuronidase ( GUS) , since the excitation of QDs was perfectly overlapped with the absorption of the substrate of GUS, namely 4-nitrophenyl-β-D-glucuronide ( PNPG) . In addition, the phosphorescence emission from Mn-doped ZnS QDs could eliminate the fluorescence background from biological samples. Therefore, a simple turn-on phosphorescent GUS assay was developed, with the linear range of 10-300 U/L and limit of detection of 7 U/L (S/N=3).