Dual-targeting surface-enhancement Raman scattering tags based on silver nanocubes for early diagnosis of pheochromocytoma.

Pheochromocytoma (PCC), a rare tumor, often develops distant metastases after diagnosis, delaying early intervention treatment. In order to overcome the limitations of traditional diagnostic methods, dual-targeting Surface-Enhancement Raman Scattering (SERS) cytosensor was developed to identify and detect PCC-CTCs from peripheral blood. Meta-iodobenzylguanidine (MIBG) and octreotide-2,2',2″,2'''- (1,4,7,10 -tetraazacyclododecane-1,4,7,10-tetrayl) tetraacetic acid (DOTA) functionalized magnetic Fe3O4 and Ag-DTNB were prepared as capture probe and signal probe for SERS signal export, respectively. Ag nanocubes (AgNCs) as Raman active substrate offer an enhanced electromagnetic field, which could effectively enhance the signal intensity of DTNB and potentially realize trace analyte detection. The obtained SERS fingerprint spectroscopy possessed the characteristic of high sensitivity and resolution in the concentration range from 3.0-3.0 × 106 cells mL-1, with a detection limit of 1 cell mL-1, which laterally compensated the deficiency of scarce CTCs in peripheral blood. This work provided new insight into PCC-CTCs accurate detection.