A fluorescence biosensor based on upconversion nanoparticles and metal organic frameworks for multiresidue detection and enrichment of neonicotinoid pesticides.

Neonicotinoid pesticides pose chronic risks to human health, making their monitoring critically important. Here, a fluorescence biosensor utilizing the upconversion-based metal-organic framework (ZIF-67@NaYF4:Yb, Tm) composite has been constructed for multi-residue detection and enrichment of neonicotinoid pesticides. Upconversion nanoparticles (NaYF4:Yb, Tm) act as the signal reporter for their excellent upconversion fluorescence. The metal-organic frameworks (ZIF-67) are introduced for their high specific surface. The NaYF4:Yb, Tm is prepared by the solvothermal method, and the ZIF-67 is prepared by a room-temperature methanol-based synthesis. Polyacrylic acid is modified on the surface of NaYF4:Yb, Tm using the ligand exchange method. The ZIF-67@NaYF4:Yb, Tm is obtained by a simple crosslinking method, exhibiting excellent upconversion fluorescence properties. The developed method shows low limits of detection of 3.26 × 10-4-6.11 × 10-4 mg·L-1, indicating high adsorption capacity and high selective recognition for neonicotinoid pesticides. Therefore, the newly developed fluorescence composites show great potential for future applications in the multiresidue analysis of pesticides.