High-efficiency UiO-66 decorated flower-like molecularly imprinted polymers for the selective enrichment of chrysin from propolis.

Chrysin is a common flavonoid compound with various pharmacological activities, which often exists in natural dietary sources such as propolis and honey. To selectively isolate and enrich chrysin from propolis, porous flower-like molecularly imprinted polymers nanomaterials were developed using a facile synthesis approach. The material was constructed by first decorating UiO-66 onto N-doped porous carbon flowers (NCFs), followed by coating the surface with a thin imprinting layer, yielding NCFs@UiO-66@MIPs. The scaffold material possesses a high specific surface area, large pore volume, and wide average pore diameter, endowing the synthesized NCFs@UiO-66@MIPs with a considerable affinity for chrysin. The maximum equilibrium adsorption capacity reached 117.6 mg g, with binding behavior consistent with monolayer adsorption. Compared to its structural analogues kaempferol, daidzein, quercetin, and genistein, NCFs@UiO-66@MIPs demonstrates better recognition ability and recovery for chrysin, achieving an imprinting factor of 3.73. After 20 adsorption-desorption cycles, the material retained 79.2 % of its initial adsorption capacity. Furthermore, the synthesized NCFs@UiO-66@MIPs demonstrated excellent anti-interference properties and regenerability, enabling highly selective chrysin enrichment from propolis. This work provides a promising imprinting adsorbent for the targeted extraction of bioactive ingredient from propolis and other complex dietary matrix.