Screening of Biocompatible MOFs for the Clearance of Indoxyl Sulfate Using GCMC Simulations

Indoxyl sulfate is a typical protein-bound uremic toxin, which is related to chronic kidney disease and a series of adverse effects such as cardiovascular and cerebrovascular diseases. Currently, there is still no effective method to specifically remove protein-bound urinary toxins. In this work, potential, high-performance, biocompatible metal–organic frameworks (MOFs) for adsorbing indoxyl sulfate were screened on a large scale. Then, the uptakes of indoxyl sulfate in some selected MOFs were calculated using the grand canonical Monte Carlo method. It was found that the accessible surface area, void fraction, accessible pore volume, and largest cavity diameter of MOFs are the key influential parameters. Furthermore, MOFs with aromatic ligands containing carboxylic acid groups and metal clusters show the best adsorption performance for indoxyl sulfate (>2100 mg/g), which is attributed to the negatively charged carboxyl groups, pyrrolidinyl nitrogen atoms with lone pairs of electrons, or open metal sites.