In this work, we first synthesized

In this work, we first synthesized MOF(Fe) following an reported method. 47 The TEM image (Figure 1A) shows an octahedral morphology as illustrated in the top-corner inset. The SEM image of MOF(Fe) (Figure 1B) exhibits a monodispersed size distribution centring at 200 nm (Figure 1C) in agreement with dynamic light scattering measurement (Figure S1). After incubation with different solvents (water, PBS and cell culture medium) for 12 h, as shown in the inset of Figure S1, there was no precipitation of MOF(Fe) can be observed, which indicates the good dispersity of MOF(Fe) in aqueous solution. The energy dispersive X-ray spectroscopy (EDS) (Figure S2) suggests the existence of Fe element in MOF(Fe) and the XRD analysis (Figure S3) shows it is well- crystallized with a typical XRD pattern of NH 2 -MIL-101(Fe). 51 The N 2 adsorption and desorption isotherms in Figure 1D demonstrate it has a mesoporous structure with average pore diameter of 2.2 nm and specific surface area of 174 m 2 /g, which not only enables drug loading but also providing efficient catalytic sites for the cascade reaction.