Multifunctional polymer nanoparticles: ultra bright near-infrared fluorescence and strong magnetization and their biological applications

Abstract

Multifunctional polymer nanoparticles with great promise for biomedical applications have attracted many attentions. Using an aggregation-enhanced emission (AEE) molecule DPPBPA and magnetic Fe₃O₄ as the core, and biocompatible polymer Pluronic F-127 as the encapsulation matrix, multifunctional polymer NPs Fe₃O₄/DPPBPA@F-127 were fabricated by self-assembly procedures. These NPs have bright near-infrared fluorescence λ_ex at 654 nm with a high fluorescence quantum yield of 18.3%, and strong magnetism, and superparamagnetism. With good monodispersity and biocompatibility, the NPs not only can show effective MRI ability, but also can stain in cytoplasm with a strong near-infrared fluorescent signal, as well as little toxicity to living cells, which show a very good prospect in the field of biological applications.