A lipid droplet-targeted NIR fluorescent probe for viscosity detection in Parkinson's disease

Investigating lipid droplets (LDs) is crucial for elucidating their role in biological function and the pathogenesis of related diseases, including Parkinson's disease (PD). Therefore, developing a fluorescent probe to measure LDs viscosity is crucial. To address the challenges of complex biological environments, a chemical toolbox, F-675, was introduced based on the twisted - intramolecular charge transfer mechanism. F-675 featured a large Stokes shift of 158 nm and emitted near-infrared emission at 675 nm, facilitating LDs detection with minimal biological fluorescent background. Additionally, F-675 exhibited excellent selectivity and sensitivity to changes of LDs. Furthermore, F-675 effectively detected LDs changes in PD models, ranging from cells, C. elegans and Parkin null Drosophila. These findings indicate the potential of F-675 as an effective tool for PD diagnosis.