For this purpose, the fluorescence lifetime were studied in three different cases: HER2-specific Affibody (His6-ZHER2:GS-Cys) fluorescent probe in human tumor models with high HER2 expression, HER2-specific Affibody fluorescent probe in a human tumor model with no HER2 expression, and HER2-nonspecific Affibody (His6-ZTaq:GS-Cys) fluorescent probe in human tumor models with high HER2 expression, all in the mouse model in vivo. Here, ERBB2 is linked to neoplasm.