Hydrophilic AIE-Active Tetraarylethenes for Fluorescence Sensing and Super-Resolution Imaging of Amyloid Fibrils from Hen Egg White Lysozyme

• DOI: 10.1021/acsami.1c01819
• Publication Date: 2021-04-23T02:53:11Z
• Authors: Cheng Fan; Ze-Qiang Chen; Chong Li; Ya-Long Wang; Qi Yu; Ming-Qiang Zhu
• Keywords: 0301 basic medicine; Amyloid; 0303 health sciences; 03 medical and health sciences; Microscopy, Fluorescence; Muramidase; Buffers; Hydrogen-Ion Concentration; Hydrophobic and Hydrophilic Interactions; Fluorescent Dyes

Hen egg white lysozyme (HEWL) is frequently applied as a model protein for research on protein folding, unfolding, and fibrillization identified by featured fluorescent probes. Here, a series of hydrophilic, pH-sensitive tetraarylethene (TAE)-type AIEgens are synthesized via a geminal cross-coupling (GCC) reaction and evaluated for their capabilities of fluorescence sensing and super-resolution localization imaging of HEWL fibrils. With superior optical and sensing properties, the selected TAE-type AIEgen probe is weakly emissive in aqueous media, without dependence on the pH value and buffer concentration, but exhibits "turn-on" fluorescence upon interaction with HEWL amyloid fibrils in a spontaneous and reversible way that just meets the requirement of fluorescence random switching for super-resolution imaging. The selected probe has the strongest fluorescence response to HEWL amyloid fibrils exhibiting a limit of detection of 0.59 nmol/L and enables super-resolution fluorescence imaging of amyloid aggregates with a high resolution of 40 nm.