Fig. 3
From: Two-dimensional metal-organic frameworks: from synthesis to bioapplications
a Structural illustration of lanthanide porphyrin MOFs with planar topography. b Representative image and the thickness of PPF-Gd measured by atomic force microscope. c The MRI application of as-designed PPF-Gd. Reprinted with permission from Ref. [58], Copyright 2019, China Science Press. d The Zn-TCPP nanosheets were fabricated by the surfactant-assisted synthesis method. e In vivo single-photon emission computer tomography imaging after i.v. injection of 99mTc labeled Zn-TCPP@PEG. Reprinted with permission from Ref. [85], Copyright 2019, Springer