Fig. 3

a Schematic illustration of the synthesis of CDs@ZrHf-MOF-based aptasensor for the detection of HER2 [155]. Reprinted with permission from Ref. [155], copyright 2019, Elsevier. b Schematic illustration of the synthesis of Fe₃O₄@TMU-21-MWCNT-based immunosensor for the detection of HER2 [89]. Reprinted with permission from Ref. [89], copyright 2020, Elsevier. CDs Carbon dots, BSA bovine serum albumin