Selenium-Sulfur-Doped Carbon Dots with Thioredoxin Reductase Activity

Thioredoxin reductase(TrxR)is an essential enzyme for regulating the redox balance in cells,promoting cell proliferation,and inhibiting cellular apoptosis.The biochemical pathway of TrxR metabolism involves a series of selenium-sulfur(Se-S)dynamic chemistry.Theoretically,nanomaterials with Se-S dynamic bonds could exhibit TrxRmimetic activities to tune TrxR activity,affecting cellular activities.Herein,we report the fabrication of Se-S-doped carbon dots(Se-S-CDs),synthesized by a facile hydrothermal method.The Se-S-CDs exhibited good stability and solubility in an aqueous solution,with a quantum yield of 13.27%.The doping of Se-S bonds endowed the Se-S-CDs with great capability of enhancing the TrxR activity,and consequently,a remarkable promotion of cell viability.The significance of Se-S bonds,as well as CDs’role as matrices,are discussed.Moreover,the Se-S-CDs could also revive the cells from the damage induced by oxidative stress.The abovementioned properties demonstrated the potential of the Se-S-CDs for cells and tissues culturing,solving the poor cell viability issue,which is desperately needed for organ transplantation and revitalization of prematurely aging cells,especially those exposed to oxidative stress.