Recent research progress in galactose-based fluorescent probes for detection of biomarkers of liver diseases

The liver is the largest detoxification organ in the human body, with an array of functions that help support metabolism, immunity, digestion, and vitamin storage, among other functions, and maintains the health and stability of the internal environment. Liver injury causes the concentration fluctuation of related biomarkers, small molecules, and enzymes, and in turn, the structure and function of the liver are changed by those alterations. With the principles of early detection, early diagnosis, and early treatment, it is crucial to design and synthesise a tool for detecting related biomarkers during liver damage and lesion, among which fluorescent probes have attracted attention in recent years. In the course of liver diseases, the asialoglycoprotein receptors (ASGPR) are overexpressed on the hepatoma cells, which can specifically recognize the galactose variant. Several galactose-based fluorescent probes have been developed to target hepatocytes via specific receptor-mediated endocytosis and release fluorophores after reacting with specific small molecules and enzyme biomarkers. The change in fluorescence intensity reflects the level of substances, such as reactive oxygen species, reactive nitrogen species, reactive sulfur species, enzymes or metal ions, etc. The application of fluorescent probes in vivo can aid in monitoring the dynamic changes of endogenous and exogenous biomarkers. This Highlight provides an update on the progress, limitations, and prospects of galactose-based fluorescent probes applications in the early diagnosis of liver diseases.