Fig. 5

a Schematic illustration of the complexation competition approach for the detection of CYFRA21-1 based on ZIF-8 [189]. Reprinted with permission from [189], copyright 2020, Elsevier. b Schematic illustration of the synthesis of the CD-MOF@Ru(bpy)₃²⁺ nanostructure for detecting CYFRA21-1 using an ECL strategy [190]. Reprinted with permission from Ref. [190], copyright 2021, Elsevier. c Schematic illustration of immunosensor and ECL detection of CYFRA21-1 [191]. Reprinted with permission from Ref. [191], copyright 2022, Elsevier. CD Cyclodextrin, Pd-ZIF-67@LDH Pd NPs functionalized Ni-co layered double hydroxide, MBs magnetic beads