Elsevier

Analytica Chimica Acta

Volume 1106, 15 April 2020, Pages 42-51
Analytica Chimica Acta

Boronic acid-decorated metal-organic frameworks modified via a mixed-ligand strategy for the selective enrichment of cis-diol containing nucleosides

https://doi.org/10.1016/j.aca.2020.01.048Get rights and content

Highlights

  • Magnetic Zr-MOFs composites were synthesized via assembly original ligand and –B(OH)2 fragments as functional groups.

  • The combination of unique properties of MOFs with magnetic separation property simplifies adsorption process.

  • The as-prepared adsorbent exhibits excellent performance for enrichment of nucleosides.

  • Pre-installation strategy basing on boronic acid functionalized can be adopted to a wider application in MOFs.

Abstract

Functional metal–organic frameworks (MOFs) constructed via a pre-installation strategy of introducing mixed organic ligands have attracted considerable interest in various fields. In the present study, boronic acid decorated magnetic Zr-MOFs were successfully synthesized by introducing 3-carboxyphenylboronic acid ligands as fragments. The prepared material was used as an adsorbent for the enrichment of cis-diol-containing nucleosides. The adsorbent has excellent performance with regard to the enrichment and separation of the nucleosides. This may be attributed to its abundant boronic acid functional groups, and the convenience of magnetic separation it provides. The obtained material was chemically stable over a large pH range. The degree of linearity of the nucleosides was excellent (0.02–10 μg mL−1), and the detection and quantification limits were low (0.006–0.016 μg mL−1 and 0.02–0.05 μg mL−1, respectively). Furthermore, it was possible to attain adsorption equilibrium within 10 min. The high efficiency of this method makes it suitable for the successful extraction of nucleosides from human urine samples, with satisfactory recoveries of 88–146%, and 1.7–9.4% precision. We believe that the fabricated functional magnetic MOFs have great potential for the analysis of other cis-diol-containing target, and the pre-installation strategy could be adapted for the wider application of MOFs.

Introduction

Saccharides, glycoproteins, catecholamines, and nucleosides are typical cis-diol biomolecules that play essential functional or structure roles in living organisms [1,2]. Studies of cis-diol containing biomolecules are of great biomedical and clinical significance [[3], [4], [5]]. Nucleosides, which are excreted in the urine, are considered potential biomarkers of the immune response to oncological processes [[6], [7], [8]]. Their plasma levels are used to evaluate oxidative stress. Liquid chromatography (LC) and mass spectrometry (MS) techniques have developed rapidly, and are widely used for the analysis of cis-diol compounds. They have high sensitivity and identification capacity, but the direct analysis of biological fluids remains difficult owing to the complex matrix of biological fluids [9,10]. Therefore, reliable and efficient sample preparations for the separation and determination of nucleosides and other cis-diol-containing targets in biological fluids are consequently essential. In recent years, boronate-based affinity isolation has gained increasing research interest [[11], [12], [13], [14]]. Boron affinity refers to the formation of stable cyclic esters from boronic acid and cis-diol compounds under alkaline conditions. Various materials decorated with boron affinity functional groups have been developed for the enrichment and separation of cis-diol-containing compounds. These include: mesoporous silica [[15], [16], [17], [18]], monoliths [[19], [20], [21]], polymers [22], and magnetic nano-composites [[23], [24], [25], [26], [27], [28]]. However, multistep synthesis procedures are usually needed to modify the boronic acid groups on the surfaces of the functionalized materials. Moreover, the low modification efficiency of boronic acid functional groups may limit their application. Therefore, the development of novel materials with abundant boronic acid active sites may improve the separation of cis-diol compounds.

Metal–organic frameworks (MOFs) comprise crystalline porous materials that are formed by inorganic metal nodes and organic linkers. In comparison with traditional porous materials, MOFs feature high porosity, abundant pore structure, and a tunable framework composition. These advantages have qualified MOFs for use in various areas, such as gas storage [29], catalysis [30], enzyme immobilization [31], sensors [32], and sample preparation [33,34]. More recently, functional MOFs based on the pre-installation of ligands containing functional groups have attracted considerable attention in biological applications [35,36]. Two ligands, the original ligand and its fragment are co-assembled and crystallized by one pot synthesis into one MOF, which retain the structure of the parent MOF. This mixed-ligand strategy greatly simplifies the synthesis procedure and introduces specific functional groups. Ligands containing boronic acid functional groups have been used to construct MOFs [[37], [38], [39], [40]]. MOFs are highly porous and are formed by adjustable ligand assembly. Therefore, MOFs containing boronic acid functional groups have a large number of active –B(OH)2 sites, which endow them with enhanced separation selectivity and adsorption capacity.

The UiO-66 framework, a kind of Zr-based MOF, would be suitable for the construction of boronic acid functionalized MOFs by a pre-installation strategy, owing to its superior stability, which makes it relatively resistant to attack by water and acidic or alkaline reactants [41,42]. The extraordinary chemical, thermal, and aqueous stability of UiO-66 would enable it to bear the assembly of ligand fragmentation. Furthermore, many MOFs have been successfully combined with magnetic particles and used as sorbent for magnetic extraction [37,[43], [44], [45]]. Such magnetic adsorbents greatly improve treatment efficiency because they facilitate the ready recovery of material from the matrix [[46], [47], [48], [49]]. Magnetic MOFs have both the excellent properties of magnetic cores for rapid and simple separation process and properties of MOF shells for efficient and selective enrichment.

Herein, we report the successful preparation of novel magnetic MOFs designated MNPs@Zr-MOFs-BA (MNPs stands for Fe3O4@SiO2)with active boronic acid sites. The MOFs were assemble from an original ligand with –B(OH)2 fragments as functional groups. The obtained composites have excellent chemical stability over a large pH range and are suitable for use as adsorbents for the enrichment and separation of nucleosides. The adsorbents have great performance with regard to the enrichment of nucleosides, and are potential candidates for the practical separation of cis-diol targets.

Section snippets

Chemicals

FeCl3·6H2O, ZrCl4, 3-carboxyphenylboronic acid (3-CPBA), tetraethyl orthosilicate (TEOS), and HPLC-grade methanol were obtained from J&K Scientific (Beijing, China). Terephthalic acid (TPA) and the four nucleosides were purchased from Tokyo Chemical Industry Co., Ltd. (Shanghai, China). The formic acid solution was from Acros Organics (Belgium). Anhydrous sodium acetate, ethylene glycol, dimethyl formamide (DMF), NH4Cl and NH3·H2O solution were supplied by Beijing Chemical Reagent Co., Ltd.

Synthesis and characterization of MNPs@Zr-MOFs-BA

The MNPs@Zr-MOFs-BA materials were synthesized by modifying the MOFs on the TEOS coated magnetic particles. The magnetic particles were synthesized by solvothermal method. The size of magnetic particles synthesized by solvothermal method is generally much larger than that of magnetic particles synthesized by co-precipitation method. Magnetic particles with large-size were used in our research, mainly because larger-size magnetic particles possess better magnetic responsiveness which can

Conclusions

In summary, a novel boronic acid functional magnetic MOF composite (MNPs@Zr-MOFs-BA) was successfully prepared via a pre-installation strategy in which a 3-carboxyphenylboronic acid ligand was introduced as a functional group. The obtained material exhibites favorable pH tolerance; the crystals remain intact over large pH range. Moreover, the adsorption rate is rapid, and the adsorption equilibrium can be achieved within a few minutes. Owing to its excellent chemical stability, abundant boronic

CRediT authorship contribution statement

Ruiqi Zhang: Conceptualization, Methodology, Validation, Investigation, Writing - original draft. Zhen Wang: Methodology, Validation. Tiefeng Wang: Methodology, Investigation. Ping Su: Conceptualization, Writing - original draft. Yi Yang: Conceptualization, Writing - original draft.

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgments

This work was supported by National Natural Science Foundation of China (Grant No. 21675008) and the Fundamental Research Funds for the Central Universities (No.XK1802-6).

References (57)

  • H. He et al.

    Facile synthesis of a boronate affinity sorbent from mesoporous nanomagnetic polyhedral oligomeric silsesquioxanes composite and its application for enrichment of catecholamines in human urine

    Anal. Chim. Acta

    (2016)
  • H. Li et al.

    Silica stationary phase functionalized by 4-carboxy-benzoboroxole with enhanced boronate affinity nature for selective capture and separation of cis-diol compounds

    Anal. Chim. Acta

    (2017)
  • C. Kip et al.

    Isolation of RNA and beta-NAD by phenylboronic acid functionalized, monodisperse-porous silica microspheres as sorbent in batch and microfluidic boronate affinity systems

    Colloids Surf., B

    (2019)
  • H. Li et al.

    Preparation of a boronate affinity silica stationary phase with enhanced binding properties towards cis-diol compounds

    J. Chromatogr. A

    (2016)
  • Q. Dong et al.

    Boronate affinity monolith via two-step atom transfer radical polymerization for specific capture of cis -diol-containing compounds

    Eur. Polym. J.

    (2018)
  • C. Zhou et al.

    A hybrid monolithic column based on boronate-functionalized graphene oxide nanosheets for online specific enrichment of glycoproteins

    J. Chromatogr. A

    (2017)
  • S. Jin et al.

    An inorganic boronate affinity in-needle monolithic device for specific capture of cis-diol containing compounds

    Talanta

    (2018)
  • Y. Ji et al.

    Facile fabrication of zwitterionic magnetic composites by one-step distillation-precipitation polymerization for highly specific enrichment of glycopeptides

    Anal. Chim. Acta

    (2019)
  • H. Zhu et al.

    Magnetic nanoparticles combining teamed boronate affinity and surface imprinting for efficient selective recognition of glycoproteins under physiological pH

    Chem. Eng. J.

    (2018)
  • M.-Y. Shi et al.

    Copper-based two-dimensional metal-organic framework nanosheets as horseradish peroxidase mimics for glucose fluorescence sensing

    Anal. Chim. Acta

    (2019)
  • W. Ma et al.

    Applications of metal-organic frameworks as advanced sorbents in biomacromolecules sample preparation

    Trac. Trends Anal. Chem.

    (2018)
  • F. Wei et al.

    In situ fabricated porous carbon coating derived from metal-organic frameworks for highly selective solid-phase microextraction

    Anal. Chim. Acta

    (2019)
  • K. Sun et al.

    Functionalization of mixed ligand metal-organic frameworks as the transport vehicles for drugs

    J. Colloid Interface Sci.

    (2017)
  • S. Liu et al.

    pH-responsive magnetic metal-organic framework nanocomposite: a smart porous adsorbent for highly specific enrichment of cis-diol containing luteolin

    Chem. Eng. J.

    (2018)
  • H. Gholami et al.

    Column packing elimination in matrix solid phase dispersion by using water compatible magnetic molecularly imprinted polymer for recognition of melamine from milk samples

    J. Chromatogr. A

    (2019)
  • M. Arabi et al.

    Novel strategy for synthesis of magnetic dummy molecularly imprinted nanoparticles based on functionalized silica as an efficient sorbent for the determination of acrylamide in potato chips: optimization by experimental design methodology

    Talanta

    (2016)
  • A.R. Bagheri et al.

    Dummy molecularly imprinted polymers based on a green synthesis strategy for magnetic solid-phase extraction of acrylamide in food samples

    Talanta

    (2019)
  • J. Huang et al.

    Grafting l-valine on polyamidoamine dendrimer-modified magnetic microspheres for enantioselective adsorption of dansyl amino acids

    Colloid. Surface. A

    (2016)
  • Cited by (27)

    View all citing articles on Scopus
    View full text