A Multi-Domain Affinity Metal Organic Polymer-MXene Heterostructure for Superior Advanced Antibody Separation

Accurate acquisition of antibody proteins plays a critical role in clinical therapy and biomedical application. Herein, a hierarchical heterostructure framework is engineered through the interfacial polymerization of a polyhedral oligomeric silsesquioxane (POSS)-based metal organic polymer on MXene (FePMX) for the separation of IgG antibody. Benefiting from the hierarchical heterostructure and abundant surface functionalities of FePMX, the recognition specificity and adsorption selectivity are significantly enhanced under the appropriate ionic strength. Furthermore, multivalent coordination and hydrophilic, hydrophobic, and electrostatic interactions by FePMX synergistically empower the multiple domain targeting of IgG, including Fc and Fab fragments. The high affinity of FePMX toward IgG is well substantiated by a dissociation constant (K_d) of 5.08 × 10^-7 M. Superior selective enrichment factor (193.75) and high uptake capacity (1784.2 mg g^-1) are also achieved, enabling the efficient separation of IgG from complex biological samples with approximately 95.4% protein purity. This study furnishes a reliable approach for specific antibody purification and highlights the remarkable potential of multidomain affinity carriers in the fields of bioanalytics and pharmaceutic research.