Bioluminescence Sensing of γ-Glutamyltranspeptidase Activity In Vitro and In Vivo

γ-Glutamyltranspeptidase (GGT) is an important tumor biomarker but using a bioluminescence (BL) probe to real time monitor its activity has not been reported. Herein, we rationally designed two GGT-cleavable BL probes Glu-AmLH 2 ( 1 ) and Glu- p -aminobenzyloxycarbonyl-AmLH 2 ( 2 ), and successfully applied them for sensing GGT activity with high sensitivity and excellent selectivity both in vitro and in vivo. The results indicated that, although 2 had lower background BL signal than 1, GGT had higher catalytic efficiency for 1 than 2, and 1 was superior to 2 for sensing GGT activity in living cells and tumors. We envision that our probe 1 could be widely applied for the diagnosis of important GGT-related diseases in animal models in the near future.