Adsorption of tryptophan by covalent organic frameworks

Abstract Hemoperfusion based on adsorption has been widely used to remove the blood toxins of patients with hepatic encephalopathy. It is important to develop adsorbents with high adsorption capacity, and specific adsorption performance for toxins is highly desired for hemoperfusion. Herein, we evaluate the tryptophan adsorption performance of four kinds of covalent organic frameworks (COFs) by powder X-ray diffraction (PXRD), high-performance liquid chromatography (HPLC), and so on. Benefitting from the abundant pore, suitable pore size, and attractive effect between tryptophan and hydroxy groups in COFs, TAPB-DHTA-COF and TAPT-DHTA-COF with abundant hydroxy groups show remarkable adsorption performance for tryptophan, which is superior to commercial activated carbon. Furthermore, the selective adsorption of COF does not affect other components in the blood, thus avoiding the occurrence of other diseases. Therefore, COFs offer a promising platform for the adsorption of toxins in hemoperfusion.