Abstract

A facile and mild method based on self-assembled lysozyme (LYZ) to fabricate bifunctional MNPs@UIO-66-Arg core-shell-satellite nanocomposites (CSSNCs) is reported for the high-efficiency enrichment of phosphopeptides. Under physiological conditions, LYZ rapidly self-assembled into a robust coating on Fe₃O₄@SiO₂ magnetic nanoparticles (MNPs) with abundant surface functional groups, which effectively mediate heterogeneous nucleation and growth of UIO-66 nanocrystals. Well-defined MNPs@UIO-66 CSSNCs with stacked pores, showing high specific surface area (333.65 m² g^− 1) and low mass transfer resistance, were successfully fabricated by fine-tuning of the reaction conditions including reaction time and acetic acid content. Furthermore, the UIO-66 shells were further modified with arginine to obtain bifunctional MNPs@UIO-66-Arg CSSNCs. Thanks to the unique morphology and synergistic effect of Zr-O clusters and guanidine groups, the bifunctional MNPs@UIO-66-Arg CSSNCs exhibited outstanding enrichment performance for phosphopeptides, delivering a low limit of detection (0.1 fmol), high selectivity (β-casein/BSA, mass ratio 1:2000), and good capture capacity (120 mg g^− 1). The mechanism for phosphopeptides capture may attribute to the hydrogen bonds, electrostatic interactions, and Zr–O–P bonds between phosphate groups in peptides and guanidyl/Zr-O clusters on bifunctional MNPs@UIO-66-Arg CSSNCs. In addition, the small stacking pores on the core-shell-satellite architecture may selectively capture phosphopeptides with low molecular weight, eliminating interference of other large molecular proteins in complex biological samples.

Graphical Abstract

摘要

据报道，一种基于自组装溶菌酶（LYZ）的简便温和的方法来制造双功能MNP@UIO-66-Arg核-壳-卫星纳米复合材料（CSSNC），用于高效富集磷酸肽。在生理条件下，LYZ在具有丰富表面官能团的Fe ₃ O ₄ @SiO ₂磁性纳米粒子（MNP）上快速自组装成坚固的涂层，有效介导UIO-66纳米晶体的异质成核和生长。通过微调反应时间和乙酸含量等反应条件，成功制备了具有堆叠孔的结构清晰的MNP@UIO-66 CSSNC，具有高比表面积（333.65 m ² g ^{- 1} ）和低传质阻力。此外，UIO-66壳进一步用精氨酸修饰以获得双功能MNPs@UIO-66-Arg CSSNCs。得益于Zr-O簇和胍基的独特形态和协同效应，双功能MNP@UIO-66-Arg CSSNC对磷酸肽表现出出色的富集性能，具有低检测限（0.1 fmol）、高选择性（β-酪蛋白/BSA，质量比1:2000)，具有良好的捕获能力(120 mg g ^{− 1} )。磷酸肽捕获的机制可能归因于肽中磷酸基团与双功能 MNPs@UIO-66-Arg CSSNC 上的胍基/Zr-O 簇之间的氢键、静电相互作用和 Zr-O-P 键。此外，核-壳-卫星结构上的小堆积孔可以选择性地捕获低分子量的磷酸肽，消除复杂生物样品中其他大分子蛋白质的干扰。