Fig. 2

a Schematic illustration of core-shell MOF-based EIS aptasensor for cascade catalysis-initiated radical polymerization stimulated signal intensification for CEA detection [152]. Reprinted with permission from Ref [152], copyright 2017, Elsevier. b Schematic illustration for the fabrication of CdS QDs@MOF and TEOA@Au aptasensor for CEA detection [154]. Reprinted with permission from Ref. [154], copyright 2022, Elsevier. IPs Insoluble precipitates, DAB 3,3-diaminobenzidine, TEOA triethanolamine