Early diagnosis and
therapy are clinically crucial in decreasing mortality from
breast carcinoma. However, the existing probes have difficulty in accurately identifying the margins and contours of
breast carcinoma due to poor sensitivity and specificity. There is an urgent need to develop high-sensitive
fluorescent probes for the diagnosis of
breast carcinoma and for differentiating
tumors from normal tissues during surgery. β-
Galactosidase is a significant
biomarker, whose overexpression is closely associated with the progression of
breast tumors. Herein, we have constructed a β-
galactosidase-activated
fluorescent probe NIR-βgal-2 through rational design and molecular docking engineering simulations. The probe displayed superior sensitivity (detection limit = 2.0 × 10-3 U/mL), great affinity (Km = 1.84 μM), and catalytic efficiency (kcat/Km = 0.24 μM-1 s-1) for β-
galactosidase. Leveraging this probe, we demonstrated the differentiation of
cancer cells overexpressing β-
galactosidase from normal cells and then applied the probe for intraoperative guided excision of
breast tumors. Moreover, we exhibited the application of NIR-βgal-2 for the successful resection of orthotopic
breast tumors by "in situ spraying" and monitored a good prognostic recovery. This work may promote the application of
enzyme-activated near-infrared
fluorescent probes for the development of
carcinoma diagnosis and
image-guided surgery.