Dual-functional AIE fluorescent probes for imaging β-amyloid plaques and lipid droplets

Alzheimer's disease (AD) is a chronic neurodegenerative disease. Better imaging and early diagnosis of biomarkers of AD is extremely important for therapeutic interventions. The amyloid cascade hypothesis and its revised version identify insoluble beta-amyloid deposition as a good diagnostic biomarker for AD. Moreover, lipid droplets may also act as an auxiliary biomarker related to AD pathology based on recent studies. Herein, two quinoline-based AIE probes were designed and synthesized for the imaging of A beta plaques and lipid droplets. The probes exhibited remarkable turn-on fluorescence enhancements with the A beta aggregates. The lipid droplets-targeting probe FB exhibited high selectivity and binding affinity towards the A beta aggregates with a detection limit as low as 26.9 nM. Furthermore, FB was capable of readily imaging A beta plaques and lipid droplets at the cellular level and in brain sections of transgenic AD mice. The probe FB can serve as a promising tool for developing early diagnosis and innovative therapeutics of AD. (C) 2020 Elsevier B.V. All rights reserved.