NBD-based fluorescent probes for separate detection of cysteine and biothiols via different reactivities

NBD-based fluorescent probes that can separately detect cysteine and biothiols via different reactivities have been rationally designed and synthesized. The probes can be applied to kinetically distinguish cysteine from other biothiols at 30 min, and to detect all biothiols at 3 h in living cells.