Brightness-constant solvatochromic dye for ratiometric fluorescent imaging of lipid dynamics in developing zebrafish

• Published in: Sensors and actuators. B, Chemical Chemical, 2024-10, Vol.417, p.136155, Article 136155
• Main Authors: Wang, Guangying, Qiao, Qinglong, Xu, Ning, Wang, Xiang, Bao, Pengjun, Zhang, Yinchan, Liu, Xiaogang, Xu, Zhaochao
• Format: Article
• Language: English
• Subjects: Constant brightness; Lipid dynamics; Ratiometric fluorescent probe; Zebrafish
• ISSN: 0925-4005
• DOI: 10.1016/j.snb.2024.136155

Lipids play a crucial role in the growth and development of organisms. However, the lack of effective chemical tools for lipid imaging has hindered a comprehensive understanding of the dynamic changes in lipid content and types in organisms. Here, we introduce a brightness-constant, lipid droplet-targeting ratiometric fluorescent probe called PAA for visualizing dynamic lipid changes during zebrafish growth and development. PAA was an ultra-stable dimer composed of two carbonylpyrenes. Despite variations in polarity, its absorption spectra, quantum yield and fluorescence brightness remained consistent. However, only fluorescence emission wavelength underwent redshift with increasing polarity. These properties enabled stable lipid imaging throughout the entire live zebrafish and allowed for the identification of lipid polarity using ratiometric fluorescence. Furthermore, PAA revealed changes of lipid composition in developing zebrafish. From 3–5 days post fertilization (dpf), zebrafish with undeveloped digestive organs exhibited a gradual decrease in overall lipid content and a reduction in lipid polarity. Subsequently, as the digestive organs fully developed (6–8 dpf), zebrafish were fed with paramecium, resulting in a gradual increase in overall lipid content and lipid polarity. Moreover, starvation experiments indicated that overall lipid content and polar lipids increased in zebrafish fed with paramecium. The successful application of PAA in visualizing lipid dynamics in zebrafish provides new avenues for studying lipid physiology and pathophysiology in living systems. [Display omitted] •The emission of PAA red-shifts with increased polarity, but the intensity remains unchanged.•Selective fluorescence imaging of lipid droplets enables imaging of lipids in zebrafish.•Visualize dynamic lipid changes during zebrafish growth and development.•Identification of lipid polarity using ratiometric fluorescence.