Hierarchical Mesoporous Metal-Organic Frameworks with Boric Acid Sites on the Inner Surface of Small Mesopores for the Extraction of Nucleotides in Human Plasma Samples.

In this work, a boronate affinity-functionalized hierarchical mesoporous metal-organic framework adsorbent with boronate sites only in the small mesopore has been structured based on UiO-66@FeO. The introduction of large mesopores in the adsorbent can promote the diffusion of small -diol-containing compounds (-diols) into small mesopore channels, and the removal of the adsorption sites on the external surface of materials and in large mesopores can enhance the size-exclusion effect of the adsorbent. In addition, the adsorbent has faster adsorption kinetics and excellent selectivity to small -diols. Finally, a magnetic dispersive solid-phase extraction coupled with high-performance liquid chromatography was established for the enrichment and detection of nucleotides in plasma. Four nucleotides achieve the recoveries from 93.25 to 118.79%, the limits of detection from 0.35 to 1.26 ng·mL, and the intra-day and inter-day relative standard deviations of less than 10.2%. In conclusion, this method can be directly used for the detection of small -diol targets in complex biological samples without protein precipitation prior to the extraction.