Recent process in organic small molecular fluorescent probes for tracking markers of tumor redox balance

Exploring the redox balance in tumor region is of great significance for clarifying the pathogenesis of tumors and finding methods for the treatment of tumors. Tumors can maintain specific redox balance by expression of some types of reactive oxygen species (for instance O2•−, H2O2, ONOO−, etc), and reducing substances (GSH, H2Sn, Cys). These substances can thus be used as markers to identify the changes in redox balance in cancer cells or tumor microenvironments. However, their high reactivity makes them difficult to be rapidly detected in-situ in biosystems. To solve this problem, various types of organic small molecular fluorescent probes (OSMFPs) have been developed relying on fluorescence imaging technology. In this review, we have systematically introduced the recent progress about OSMFPs that could detect tumor redox balance and proposed some outlooks based on our opinions. This review provide important reference for further development of OSMFPs-based detection methods for redox balance.