Organic Nanoprobes for Fluorescence and 19F Magnetic Resonance Dual‐Modality Imaging

Abstract

Multimodal imaging techniques have been demonstrated to be greatly advantageous in achieving accurate diagnosis and gained increasing attention in recent decades. Herein, we present a new strategy to integrate the complementary modalities of 19F magnetic resonance imaging (19F MRI) and fluorescence imaging (FI) into a polymer nanoprobe composed of hydrophobic fluorescent organic core and hydrophilic fluorinated polymer shell. The alkyne‐terminated fluorinated copolymer (Pn) of 2,2,2‐trifluoroethyl acrylate (TFEA) and poly(ethylene glycol) methyl ether acrylate (PEGA) was first prepared via atom transfer radical polymerization (ATRP). The PEGA plays an important role in both improving 19F signal and modulating the hydrophilicity of Pn. The alkynyl tail in Pn is readily conjugated with azide modified tetra‐phenylethylene (TPE) through click chemistry to form azo polymer (TPE‐azo‐Pn). The core‐shell nanoprobes (TPE‐P3N) with an average particle size of 57.2 ± 8.8 nm are obtained via self‐assembly with ultrasonication in aqueous solution. These nanoprobes demonstrate high water stability, good biocompatibility, strong fluorescence and good 19F MRI performance, which present great potentials for simultaneous fluorescence imaging and 19F–MR imaging.