Uniformly swelling Eu(NTA)3Phen into PS microspheres through an EGDMA-crosslinked polymer networks: Towards high EQE fluorescence and high sensitivity IVD

Lanthanide complexes based fluorescent microspheres are widely used in lateral flow immunoassay (LFIA) measurements of small melecules, such as methamphetamine (MET), due to their efficient fluorescence. However, the easily occurred aggregation of lanthanide complexes often leads to concentration quenching effect of fluorescence, which severely deteriorate the biodetection performance of fluorescent microspheres. Here, in order to optimize the distribution of lanthanide complexes, the crosslinked agent dimethacrylate (EGDMA) is introduced in the microspheres polymerization. By adjusting the concentration of EGDMA, the aggregation of lanthanide complexes is reduced, which inhibits fluorescence quenching effect and enhances fluorescence intensity of the fluorescent microspheres. Such fluorescent microspheres thus achieve highly sensitive detection of MET, with showing a detection limit of 0.048 ng mL −1 with excellent stability. This study provides a new idea for the optimal design of lanthanide complexes dispersed fluorescent latex beads, which is expected to promote the development of advanced In Vitro Diagnostics (IVD) technologies to rapid and precise screening of small molecules.