γ-Glutamyl transpeptidase activatable probe for fluorescence-assisted guiding surgery and imaging of human tumors via spraying

γ-Glutamyltranspeptidase (GGT) is an ectoenzyme anchored on the surface of the cell membrane, and it is closely associated with many diseases. Abnormal expression (>36 U/L) of GGT is involved in the progression of tumors and can act as a biomarker for tumor diagnosis. Here, we presented a series of GGT-activatable fluorescent probes, the P1, the P2 and the P3. By investigating the in vitro properties of the probes, P3 demonstrated the most sensitivity and better water solubility, which benefited from the introduction of the self-elimination moiety of p-aminobenzyl alcohol and the propanesulfonic acid moiety. Importantly, P3 was able to clearly delineate tumor boundaries in live tumor-bearing mice and clinical human liver tissue specimens by spraying in situ, which facilitated accurate resection of tumors under fluorescence guidance. The proposed enzyme-activated fluorescent probe has potential as a surgical resection tool in image-guided surgery.