Fig. 8. (a) Schematic synthetic process of Co-Fc@GOx (nanoscale Co-ferrocene metal–organic framework, Co-Fc NMOF) as a cascade Fenton and enzymatic reaction nanoplatform for promoted ˙OH generation. (b–d) SEM, TEM image, and elemental mapping image of Co-Fc@GOx NMOF. Reproduced with permission from ref. 51. Copyright 2020, Wiley-VCH. (e) Schematic illustration of acid degradation and the rapid ion exchange reaction during the nanotheranostic agents (NTAs) synthesis process. K_sp: stability constant. (f) TEM images of PBAM (a MIL-100 (Fe)-coated Prussian blue (PB) analogue (K₂Mn[Fe(CN)₆])) in different pH conditions (pH = 5.0, 6.5, and 7.4). Scar bar: 100 nm. Reproduced with permission from ref. 52. Copyright 2020, Wiley-VCH. (g) Schematic synthetic process of MnFe₂O₄@MOF. (h) TEM image of MnFe₂O₄ NP. (i) SEM, TEM (inset), (j) high-resolution TEM, and (k) elemental mapping images of MnFe₂O₄@MOF. Reproduced with permission from ref. 53. Copyright 2019, Wiley-VCH.