Self‐Assembly of Anionic Porphyrins and Alkaline or Alkaline Earth Metal Ions Mediated by Cucurbit[7,8]uril

Abstract Nanoscaled coordination polymers based on biologically prevalent ions have potential applications in drug delivery and biomedical imaging. Herein, coordination polymer nanoparticles of anionic porphyrins, including meso ‐tetra(4‐carboxyphenyl)‐porphyrin (H 2 TCPP 4− ) and meso ‐tetra(4‐sulfonatophenyl)‐porphyrin (H 2 TPPS 4− ), and alkaline or alkaline earth metal cations, such as K + and Ca 2+ , were constructed in aqueous solution in the presence of cucurbit[7]uril (CB7) or cucurbit[8]uril (CB8). UV/Vis absorption and fluorescence spectroscopy, dynamic light scattering (DLS), scanning electron spectroscopy (SEM), and atomic force microscopy (AFM) were applied to explore the assembly and particle formation of porphyrin anions and metal cations mediated by CB n . The particle size depends on the kinds of CB n and metal cations and their concentrations. The uptake of H 2 TPPS 4− particles by tumor cells (A549 cells) was found to be more efficient than H 2 TPPS 4− at 37 °C, showing the application potential of such assembled particles in biology and medicine.