Key Laboratory of Advanced Mass Spectrometry and Molecular Analysis of Zhejiang Province, Institute of Mass Spectrometry, School of Material Science and Chemical Engineering, Ningbo University, Ningbo, 315211, Zhejiang, China.
National Institute of Metrology, Beijing, 100084, China.
Mikrochim Acta. 2022 Aug 15;189(9):330. doi: 10.1007/s00604-022-05394-3.
A guanidine-functionalized (GF) covalent organic framework (COF) nanocomposite has been developed by a post-synthetic approach for specific capture and separation of phosphopeptides and exosomes. The abundant binding sites on COF can immobilize a large number of gold nanoparticles (AuNPs), which can be used to react with amino groups to graft polyethyleneimine (PEI). Finally, FeO@COF@Au@PEI-GF is obtained through the reaction of PEI and guanidyl group for phosphopeptides and exosomes detection. This composite shows a low detection limit (0.02 fmol), size exclusion effect (β-casein digests:Albumin from bovine serum protein = 1:10,000), good reusability (10 cycles), and high selectivity (β-casein digests:Albumin from bovine serum digests = 1:10,000). For complex biological sample, 4 phosphopeptides can be successfully identified from human serum. Furthermore, for the first time, we used guanidyl-functionalized probe to capture exosomes in human serum, providing a new method for enriching exosomes. The above experiments showed that FeO@COF@Au@PEI-GF not only effectively enrich phosphopeptides and remove macromolecular proteins, but also successfully separate and capture exosomes. This demonstrates the great potential of this composite for the specific enrichment of phosphopeptides and isolation of exosomes.
一种胍基功能化（GF）的共价有机骨架（COF）纳米复合材料通过后合成方法制备，用于特异性捕获和分离磷酸肽和外泌体。COF 上丰富的结合位点可以固定大量的金纳米粒子（AuNPs），这些纳米粒子可以与氨基反应，接枝聚乙烯亚胺（PEI）。最后，通过 PEI 和胍基的反应，得到 FeO@COF@Au@PEI-GF，用于检测磷酸肽和外泌体。该复合材料具有较低的检测限（0.02 fmol）、尺寸排阻效应（β-酪蛋白消化物：牛血清白蛋白蛋白=1:10,000）、良好的可重复使用性（10 次循环）和高选择性（β-酪蛋白消化物：牛血清消化物=1:10,000）。对于复杂的生物样本，能够从人血清中成功鉴定出 4 种磷酸肽。此外，我们首次使用胍基功能化探针捕获人血清中的外泌体，为外泌体的富集提供了一种新方法。上述实验表明，FeO@COF@Au@PEI-GF 不仅能有效富集磷酸肽并去除大分子蛋白质，还能成功分离和捕获外泌体。这证明了该复合材料在磷酸肽的特异性富集和外泌体的分离捕获方面具有巨大的潜力。
