Selenium is the chalcogen of choice for selective reporting of thioredoxin reductase activity

The thioredoxin system is a critical regulator of redox processes across eukaryotes, but precise monitoring of its activity is made difficult by the lack of selective cellularly active probes. In this issue of Chem, Thorn-Seshold and co-workers utilize a rational design approach to develop a highly selective selenylsulfide probe for monitoring thioredoxin reductase activity in live cells.