A mesoporous silica-based probe with a molecularly imprinted polymer recognition and Mn:ZnS QDs@rhodamine B ratiometric fluorescence sensing strategy for the analysis of 4-nitrophenol.

In this study, a mesoporous silica fluorescence probe co-doped with manganese-doped zinc sulfide quantum dots (Mn:ZnS QDs) and rhodamine B (RB) and coated with molecularly imprinted polymer (MIP) has been prepared by sol-gel methods. The morphology and structure were characterized in detail by transmission electron microscopy (TEM), Fourier transform-infrared absorption spectroscopy (FT-IR) and ultraviolet-visible absorption spectroscopy (UV-vis). The probe exhibited two characteristic emission peaks at 411 nm and 582 nm, and the synchronous ratiometric fluorescence responses F411/F582 to different concentrations of 4-nitrophenol (4-NP) showed a good linear correlation in the range of 0.01-10 μmol L-1 besides achieving the sensitive detection of 4-NP with a detection limit as low as 3.0 nmol L-1 (3σ). The probe possesses the advantages of selectivity toward the target molecular structure, self-stability in the detection time domain and anti-interference ability, exhibiting excellent potential for application in 4-NP detection in different water environments.