Recent Progress in Endoplasmic Reticulum-Targetable Small-Molecule Probes for Fluorescence Sensing and Phototherapy

The endoplasmic reticulum (ER) is the most widespread organelle within eukaryotic cells, performing various essential functions such as protein synthesis, post-translational modifications, and lipid metabolism. Abnormal fluctuations of biologically active species and microenvironments in the ER can disrupt homeostasis and eventually lead to ER stress, which is closely linked to the occurrence and progression of many human diseases. Therefore, the ER has been regarded as an important analytical object as well as a promising therapeutic target in both bio sensing and biomedicine. Recently, there has been a growing interest in developing photon-excited molecular tools to uncover the physio pathological roles of ER and treat ER-related disorders. This review presents a comprehensive summary of recent advances in ER-targeted small-molecule probes and their applications for fluorescent sensing and phototherapy, mainly focusing on targeting strategies and probe design principles. Last, we discuss the challenges involved with ER-targeted probes and highlight potential prospects in this field.