Core-Shell Magnetic Particles: Tailored Synthesis and Applications

Core-shell magnetic particles consisting of magnetic core and functional shells have aroused widespread attention in multidisciplinary fields spanning chemistry, materials science, physics, biomedicine, and bioengineering due to their distinctive magnetic properties, tunable interface features, and elaborately designed compositions. In recent decades, various surface engineering strategies have been developed to endow them desired properties (e.g., surface hydrophilicity, roughness, acidity, target recognition) for efficient applications in catalysis, optical modulation, environmental remediation, biomedicine, etc. Moreover, precise control over the shell structure features like thickness, porosity, crystallinity and compositions including metal oxides, carbon, silica, polymers, and metal-organic frameworks (MOFs) has been developed as the major method to exploit new functional materials. In this review, we highlight the synthesis methods, regulating strategies, interface engineering, and applications of core-shell magnetic particles over the past half-century. The fundamental methodologies for controllable synthesis of core-shell magnetic materials with diverse organic, inorganic, or hybrid compositions, surface morphology, and interface property are thoroughly elucidated and summarized. In addition, the influences of the synthesis conditions on the physicochemical properties (e.g., dispersibility, stability, stimulus-responsiveness, and surface functionality) are also discussed to provide constructive insight and guidelines for designing core-shell magnetic particles in specific applications. The brand-new concept of "core-shell assembly chemistry" holds great application potential in bioimaging, diagnosis, micro/nanorobots, and smart catalysis. Finally, the remaining challenges, future research directions and new applications for the core-shell magnetic particles are predicted and proposed.

Diethylenetriamine assisted functionalization of boronic acid on poly GMA-MAA-DVB for selective enrichment of glycoproteins and glycopeptides

Cis-diol compounds are class of biomolecules including nucleosides, glycoproteins, saccharides, and nucleotides, which play vital roles in various biological processes. Due to low abundances of these species in the complex biological samples, their identification and analysis is difficult. Boronate affinity materials are commonly used for the isolation and enrichment of cis-diol compounds, due to their unique, facile and selective enrichment mechanism. In this study we report a selective approach to extract nucleosides, glycopeptides and glycoproteins using boronic acid functionalized GMA-MAA-DVB polymer. This novel polymer, reported for the first time in proteomics, have high BET surface area (132.8447 m² g^-1) which contribute to efficient enrichment and average pore size (20.3449 nm) to facilitates the nano confinement effect for strong interactions. Hydrophilic character of methacrylic acid and diethylenetriamine, along with inherent affinity of boronic acid for glycosylated biomolecules result in selectivity up to 1:500 for peptides and 1:1000 for glycoprotein. Binding constant for cis-diol compounds are in the range of 10^-4 to 10^-6 M and theoretical binding capacity up to 85 mg g^-1 for HRP and 180 mg g^-1 for IgG, respectively. Furthermore, boronic acid functionalized polymer (BFP) enrich glycoproteins and glycopeptides in range of 1 pg mL^-1 and 0.04 ng mL^-1 with S/N ≥ 3. Finally, material is applied to enrich the glycoproteins from healthy human saliva sample and six glycoproteins are identified.

DMSA-Functionalized Mesoporous Alumina with a High Capacity for Selective Isolation of Immunoglobulin G

A novel dimercaptosuccinic acid-functionalized mesoporous alumina (DMSA-MA) is synthesized by the dicarboxylic acid groups of dimercaptosuccinic acid molecules coordinating to the Al³⁺ ions located in the mesostructure. The as-prepared DMSA-MA composites possess a large surface area of 91.17 m²/g as well as a uniform pore size and a high pore volume of 17.22 nm and 0.23 cm³/g, respectively. DMSA coating of mesostructures significantly enhanced their selectivity for glycoprotein adsorption through a powerful hydrophilic binding force, and the maximum adsorption capacity of immunoglobulin G (IgG) can reach 2298.6 mg g^-1. The captured IgG could be lightly stripped from the DMSA-MA composites with an elution rate of 98.3% by using 0.5 wt % CTAB solution as the elution reagent. DMSA-MA is further employed as a sorbent for the enrichment of IgG heavy chain and light chain from human serum sample. SDS-PAGE assay results showed the obtained IgG with high purity compared to that of the standard solution of IgG.

Isolation and characterization of glycosylated neuropeptides

Glycosylation is one of the most ubiquitous and complex post-translational modifications (PTMs). It plays pivotal roles in various biological processes. Studies at the glycopeptide level are typically considered as a downstream work resulting from enzymatic digested glycoproteins. Less attention has been focused on glycosylated endogenous signaling peptides due to their low abundance, structural heterogeneity and the lack of enabling analytical tools. Here, protocols are presented to isolate and characterize glycosylated neuropeptides utilizing nanoflow liquid chromatography coupled with mass spectrometry (LC-MS). We first demonstrate how to extract neuropeptides from raw tissues and perform further separation/cleanup before MS analysis. Then we describe hybrid MS methods for glycosylated neuropeptide profiling and site-specific analysis. We also include recommendations for data analysis to identify glycosylated neuropeptides in crustaceans where a complete neuropeptide database is still lacking. Other strategies and future directions are discussed to provide readers with alternative approaches and further unravel biological complexity rendered by glycosylation.

A facilely synthesized glutathione-functionalized silver nanoparticle-grafted covalent organic framework for rapid and highly efficient enrichment of N-linked glycopeptides

The development of facilely synthetic materials for highly efficient enrichment of N-linked glycopeptides is essential in glycoproteome analysis. In this work, by utilizing the self-assembling of glutathione (GSH) on silver nanoparticles (Ag NPs), and the formation and dispersion of Ag NPs on a robust TpPa-1 substrate, a newly functionalized covalent organic framework (COF) called TpPa-1@Ag@GSH was synthesized via a simple two step post-synthetic modification. TpPa-1@Ag@GSH and intermediate products were confirmed and evaluated by nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, scanning electron microscopy-energy dispersive spectroscopy, Brunauer-Emmett-Teller and thermogravimetric analyses. Benefiting from the judicious selection of the substrate, the abundance of binding sites, relatively high affinity between GSH and N-linked glycopeptides, and the multivalent interactions between N-linked glycopeptides and unoccupied surfaces of Ag NPs, this porous material showed great performance in N-linked glycopeptide enrichment. By enriching N-linked glycopeptides in tryptic digests of human serum immunoglobulin G (human IgG) followed by mass spectrometry analysis, our method was proved to have good sensitivity (1 fmol), high selectivity (1 : 1500, human IgG to bovine serum albumin), high binding capacity (160 mg g-1, IgG/TpPa-1@Ag@GSH), ultra-fast capture ability (only 1 min incubation time), and good reusability (at least 5 times). It was also successfully applied to the enrichment of N-linked glycopeptides from complex biological samples. Our work improved the enrichment selectivity of COFs, reached the most rapid capture ability among off-column enrichment materials, and provided a very facile and easily popularized post-synthetic modification route for COFs in glycoproteome analysis.

Functional dual hydrophilic dendrimer-modified metal-organic framework for the selective enrichment of N-glycopeptides

Analysis of protein glycosylation remains a significant challenge due to the low abundance of glycoproteins or N-glycopeptides. Here we have synthesized an amino-functionalized metal-organic framework (MOF) MIL-101(Cr)-NH₂ whose surface is grafted with a hydrophilic dendrimer poly(amidoamine) (PAMAM) for N-glycopeptide enrichment based on the hydrophilic interactions. The selected substrate MOF MIL-101(Cr) owns high surface area which provides nice support for peptide adsorption. In addition, the MOF displayed a good hydrophilic property after being modified with amino groups. Most importantly, the grafted hydrophilic dendrimer PAMAM was firstly applied in the postsynthetic modification of MOFs. And this functionalization route using macromolecular dendrimer opens a new perspective in MOFs design. Owing to its long dendritic chains and abundant amino groups, our material displayed dual hydrophilic property. In the enrichment of standard glycoprotein HRP digestion, the functional MOF material was shown to have low detection limit (1 fmol/μL) and good selectivity when the concentration of nonglycopeptides was 100 fold higher than the target N-glycopeptides. All the results proved that MIL-101(Cr)-NH₂ @PAMAM has great potential in the glycoproteome analysis.

Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: An update for 2011-2012

This review is the seventh update of the original article published in 1999 on the application of MALDI mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2012. General aspects such as theory of the MALDI process, matrices, derivatization, MALDI imaging, and fragmentation are covered in the first part of the review and applications to various structural types constitute the remainder. The main groups of compound are oligo- and poly-saccharides, glycoproteins, glycolipids, glycosides, and biopharmaceuticals. Much of this material is presented in tabular form. Also discussed are medical and industrial applications of the technique, studies of enzyme reactions, and applications to chemical synthesis. © 2015 Wiley Periodicals, Inc. Mass Spec Rev 36:255-422, 2017.

Nanotechnology in Glycomics: Applications in Diagnostics, Therapy, Imaging, and Separation Processes

This review comprehensively covers the most recent achievements (from 2013) in the successful integration of nanomaterials in the field of glycomics. The first part of the paper addresses the beneficial properties of nanomaterials for the construction of biosensors, bioanalytical devices, and protocols for the detection of various analytes, including viruses and whole cells, together with their key characteristics. The second part of the review focuses on the application of nanomaterials integrated with glycans for various biomedical applications, that is, vaccines against viral and bacterial infections and cancer cells, as therapeutic agents, for in vivo imaging and nuclear magnetic resonance imaging, and for selective drug delivery. The final part of the review describes various ways in which glycan enrichment can be effectively done using nanomaterials, molecularly imprinted polymers with polymer thickness controlled at the nanoscale, with a subsequent analysis of glycans by mass spectrometry. A short section describing an active glycoprofiling by microengines (microrockets) is covered as well.

Preparation and application of silver nanoparticle-functionalized magnetic graphene oxide nanocomposites

Although selective enrichment of glycopeptides from complex biological samples is indispensable for mass spectrometry (MS)-based glycoproteomics, it still remains a great challenge due to the low abundance of glycoproteins and suppression of non-glycopeptides. In this study, silver nanoparticle-functionalized magnetic graphene oxide nanocomposites (GO/Fe₃O₄/PEI/Ag) were synthesized. Silver nanoparticles were generated in situ on the surface of magnetic graphene oxide using polyethylenimine as a reducing and stabilizing agent. The resulting material was used as an adsorbent for selective enrichment of glycopeptides. GO/Fe₃O₄/PEI/Ag nanocomposites offered excellent enrichment ability, which was attributed to the synergistic effect of polyethylenimine and silver nanoparticles. The nanocomposites showed superior specificity for glycopeptides even when non-glycopeptides were 100 times more concentrated than glycopeptides. The nanocomposites displayed advantages including rapid adsorption (1 min), low detection limit (25 fmol), repeatability (6 times), and high recovery (77.8%). Using these nanocomposites, 91 different glycoproteins and 136 N-linked glycopeptides were identified from among 20 μg tryptic human serum proteins and this demonstrated the superior performance of the nanocomposites for glycopeptides enrichment.

Application of Porous Materials to Carbohydrate Chemistry and Glycoscience

There is a growing interest in using a range of porous materials to meet research needs in carbohydrate chemistry and glycoscience in general. Among the applications of porous materials reviewed in this chapter, enrichment of glycans from biological samples prior to separation and analysis by mass spectrometry is a major emphasis. Porous materials offer high surface area, adjustable pore sizes, and tunable surface chemistry for interacting with glycans, by boronate affinity, hydrophilic interactions, molecular imprinting, and polar interactions. Among the materials covered in this review are mesoporous silica and related materials, porous graphitic carbon, mesoporous carbon, porous polymers, and nanoporous gold. In some applications, glycans are enzymatically or chemically released from glycoproteins or glycopeptides, and the porous materials have the advantage of size selectivity admitting only the glycans into the pores and excluding proteins. Immobilization of lectins onto porous materials of suitable pore size allows for the use of lectin-carbohydrate interactions in capture or separation of glycoproteins. Porous material surfaces modified with carbohydrates can be used for the selective capture of lectins. Controlled release of therapeutics from porous materials mediated by glycans has been reported, and so has therapeutic targeting using carbohydrate-modified porous particles. Additional applications of porous materials in glycoscience include their use in the supported synthesis of oligosaccharides and in the development of biosensors for glycans.

Efficient enrichment of glycopeptides using metal-organic frameworks by hydrophilic interaction chromatography

Selective enrichment of glycopeptides from complicated biological samples is critical for glycoproteomics to obtain the structure and glycosylation information of glycoproteins using mass spectrometry (MS), which still remains a great challenge. Hydrophilic interaction chromatography (HILIC)-based strategies have been proposed for selective isolation of glycopeptides via the interactions between the glycan of glycopeptides and the matrices. However, the application of these methods is limited by the medium selectivity of HILIC matrices. In this study, hydrophilic metal-organic frameworks (MOFs) were fabricated and used as a HILIC matrix. The cross-linked CD-MOFs (LCD-MOFs) were facilely prepared with γ-cyclodextrin as ligand and possessed nano-sized cubic structure, superior hydrophilicity, and bio-compatibility. The LCD-MOFs performance for the selective enrichment of glycopeptides from the complex biological samples were investigated with a digested mixture of human immunoglobulin G (IgG) that was used as standard samples. In the selectivity assessment, the non-glycopeptides causing ion suppression to the glycopeptides were effectively removed, the signal of glycopeptides were enhanced significantly by LCD-MOFs, and twenty glycopeptides were identified with 67 fmol of IgG digest. In addition, the resulting LCD-MOFs demonstrated the lower detection limit (3.3 fmol) with a satisfactory recovery yield (84-103%) for glycopeptide enrichment from a digest of IgG. Furthermore, a promising protocol was developed for the selective enrichment of glycopeptides from mouse liver, and 344 unique N-glycosylation sites that mapped to 290 different glycoproteins were identified in a single MS run. The results clearly demonstrated that when used in a HILIC matrix, LCD-MOFs have great potential for identifying and enriching low-abundant glycopeptides in complex biological samples.

Amine Chemistry Method for Selective Enrichment of N-Linked Glycopeptides for Glycoproteomics Analysis

An amine chemistry method was developed for the extraction of N-glycopeptides using amine-functionalized beads for glycoproteomics analysis. Two reductive amination reactions between primary amine and aldehyde were employed in this approach. The first one was to block the primary amines in the peptides by addition of formaldehyde and sodium cyanoborohydride into the peptide sample, and the second one was to couple the glycopeptides onto solid phase beads by incubating the glycopeptides containing aldehyde groups (oxidized by periodate) with the amine-functionalized beads in the presence of sodium cyanoborohydride. It was demonstrated that the blocking of primary amines in the peptides by the first reductive amination reaction prior to the periodate oxidation made the amine chemistry method very efficient and sensitive. This new method was validated by analysis of glycoprotein standards as well as proteome samples. It was found that this new method led to significant increase in the identification of N-glycosites compared with the conventional hydrazide chemistry method.

Synthesis of a hydrophilic maltose functionalized Au NP/PDA/Fe3O4-RGO magnetic nanocomposite for the highly specific enrichment of glycopeptides

A novel approach was developed to synthesize a hydrophilic thiol-terminated maltose-functionalized Au NP/PDA/Fe₃O₄-RGO nanocomposite which exhibited high selectivity and detection sensitivity in the enrichment of glycopeptides from complex samples.

Facile preparation of carbon-functionalized ordered magnetic mesoporous silica composites for highly selective enrichment of N-glycans

A novel carbon-functionalized ordered magnetic mesoporous silica composite was designed and synthesized.

Titania composite microspheres endowed with a size-exclusive effect toward the highly specific revelation of phosphopeptidome

The efficient isolation of low-abundance phosphopeptides from complicated biological samples containing a significant quantity of nonphosphopeptides and proteins is essential for phosphopeptidome research but remains a great challenge. In this Article, magnetic composite microspheres comprising a magnetic colloidal nanocrystal cluster core and a mesoporous titania shell with an average pore diameter of 3.4 nm were modified by directly coating an amorphous titania shell onto the magnetite core, followed by converting the amorphous titania shell into a crystalline structure via a hydrothermal process at 80 °C. The as-prepared magnetic mesoporous titania microspheres possess a remarkable specific surface area that is as high as 603.5 m2/g, which is an appropriate pore size with a narrow size distribution and a high magnetic responsiveness. These outstanding features imply that the composite microspheres exhibit extraordinary performance in phosphopeptidome research, including high specificity toward phosphopeptides, an excellent size-exclusion effect against phosphoproteins, exceptional enrichment capacity, and efficient separation from mixtures. Encouraged by the experimental results, we employed this method to investigate the phosphopeptidome of snake venom for the first time. A total of 35 phosphopeptides was identified from the snake venom from the family Viperidae, accounting for 75% of the total identified peptides. This result represents the largest data set of the phosphopeptidome in snake venom from the family Viperidae.

Nanotechnologies in glycoproteomics

Protein glycosylation, as an important post-translational modification, is implicated in a number of ailments. Applying proteomic approaches, including mass spectrometry (MS) analyses that have played a significant role in biomarker detection and early diagnosis of diseases, to the study of glycoproteins or glycopeptides will facilitate a deeper understanding of many physiological functions and biological pathways involved in cancer, inflammatory and degenerative diseases. The abundance of glycopeptides and their ionization potential are relatively lower compared to those of non-glycopeptides; therefore, sample enrichment is necessary for glycopeptides prior to MS analysis. The application of nanotechnology in the past decade has been rapidly penetrating into many diverse scientific research disciplines. Particularly in what we now refer to as the “glycoproteomics area”, nanotechnologies have enabled enhanced sensitivity and specificity of glycopeptide detection in complex biological fluids, which are critical for disease diagnosis and monitoring. In this review, we highlight some recent studies that combine the capabilities of specific nanotechnologies with the comprehensive features of glycoproteomics. In particular, we focus on the ways in which nanotechnology has facilitated the detection of glycopeptides in complex biological samples and enhanced their characterization by MS, in terms of intensity and resolution. These studies reveal an increasingly important role for nanotechnology in helping to overcome certain technical challenges in biomarker discovery, in general, and glycoproteomics research, in particular.

Benzoboroxole-functionalized magnetic core/shell microspheres for highly specific enrichment of glycoproteins under physiological conditions

Efficient enrichment of specific glycoproteins from complex biological samples is of great importance towards the discovery of disease biomarkers in biological systems. Recently, phenylboronic acid-based functional materials have been widely used for enrichment of glycoproteins. However, such enrichment was mainly carried out under alkaline conditions, which is different to the status of glycoproteins in neutral physiological conditions and may cause some unpredictable degradation. In this study, on-demand neutral enrichment of glycoproteins from crude biological samples is accomplished by utilizing the reversible interaction between the cis-diols of glycoproteins and benzoboroxole-functionalized magnetic composite microspheres (Fe3O4/PAA-AOPB). The Fe3O4/PAA-AOPB composite microspheres are deliberately designed and constructed with a high-magnetic-response magnetic supraparticle (MSP) core and a crosslinked poly(acrylic acid) (PAA) shell anchoring abundant benzoboroxole functional groups on the surface. These nanocomposites possessed many merits, such as large enrichment capacity (93.9 mg/g, protein/beads), low non-specific adsorption, quick enrichment process (10 min) and magnetic separation speed (20 s), and high recovery efficiency. Furthermore, the as-prepared Fe3O4/PAA-AOPB microspheres display high selectivity to glycoproteins even in the E. coli lysate or fetal bovine serum, showing great potential in the identify of low-abundance glycoproteins as biomarkers in real complex biological systems for clinical diagnoses.

Highly efficient enrichment method for glycopeptide analyses: using specific and nonspecific nanoparticles synergistically

We invented a new method for highly efficient and specific enrichment of glycopeptides using two different nanomaterials synergistically. One is boronic-acid-functionalized Fe3O4 nanoparticles, enriching glycopeptides through formation of cyclic boronate esters between the boronic acid groups and the cis-diol groups on glycopeptides. The other nanomaterial is conventional poly(methyl methacrylate) nanobeads, which have strong adsorption toward nonglycopeptides. By optimizing the proportion of these two materials, extremely high sensitivity and selectivity are achieved in analyzing the standard glycopeptides/nonglycopeptides mixture solutions. Since the washing step is not necessary for these conditions, the enrichment process is simplified and the recovery efficiency of target glycopeptides reaches 90%. Finally, this approach is successfully applied to analyze human serum with the sample volume as little as 1 μL, in which 147 different N-glycosylation peptides within 66 unique glycoproteins are identified. All these performances by the synergistic enrichment are much better than employing one specific enrichment agent alone.

A facilely synthesized amino-functionalized metal–organic framework for highly specific and efficient enrichment of glycopeptides

A facilely synthesized amino-functionalized metal–organic framework MIL-101(Cr)-NH₂ was first applied for highly specific and efficient glycopeptide enrichment.

Facile synthesis of yolk-shell magnetic mesoporous carbon microspheres for efficient enrichment of low abundance peptides

Magnetic mesoporous carbon microspheres with a yolk-shell structure (YSMMCS) have been prepared via a new in situ carbon source strategy. The material was fabricated by two shells coated onto the Fe3O4 particles; the inner dense and thick silica shell could protect the magnetic core from harsh acidic solvents as well as induce the void between the core and the outer shell for the yolk-shell structure, while the outer organosilica shell was used as the template and carbon source for in situ preparation of a carbon shell with mesoporous structure. A C18-alkyl chain was incorporated in situ as the carbon precursor efficiently, avoiding the conventional infiltration step, which was very difficult to manipulate and time-consuming with the possibility of losing the carbon precursor. The resulting yolk-shell magnetic mesoporous carbon microspheres exhibited a high surface area (273.15 m(2) g(-1)), a large pore volume (0.31 cm(3) g(-1)), and a strong magnetic response (a saturation magnetization value of 34.57 emu g(-1)). As a result of the void between the core and the outer shell and the π-π stacking effect, adsorption capacity reached 191.64 mg g(-1) by using Rhodamine B as a standard analyte, indicating the great potential application of the material as drug carriers. Owing to the inherent hydrophobicity and high surface area, the composite material showed better performance in the enrichment of peptides than a magnetic mesoporous silica material (Fe2O3@nSiO2@mSiO2). According to the LC-MS/MS results, about 51 and 29 nonredundant peptides were identified from tryptic digests of 5 nM BSA. Additionally, taking advantage of the mesoporous structure and strong magnetic response, the material was utilized to selectively extract low abundance endogenous peptides from human serum in the presence of high abundance proteins. Based on the LC-MS/MS results, 962 endogenous peptides were obtained by 2.5 mg YSMMCS relative to 539 endogenous peptides by 5 mg Fe2O3@nSiO2@mSiO2, confirming the outstanding performance of YSMMCS in peptidome analysis.

Magnetic colloidal supraparticles: design, fabrication and biomedical applications

Magnetic nanoparticles (MNPs) bear many intriguing properties such as superparamagnetism, high specific surface area, remarkable colloidal stability and biocompatibility, which evoke great interest and desire of exploration in biomedical applications. For the use in the complicated physiological environment, MNPs are still being developed to have the enhanced performances and down-to-earth practicality. Engineering of MNPs into hierarchical structures is thus proposed to create a new family of magnetic materials, magnetic colloidal supraparticles (MCSPs), which exhibit collective properties and unique nanomaterial characters. From a biomedical point of view, applicability of MCSPs is somewhat more distinctive in contrast to their primary MNPs, because MCSPs are amenable to modulation of secondary structure, promotion of magnetic responsiveness and ease of function design. As a result, MCSPs have been subject to intense researches in recent years, with the aim to develop outstanding composite materials for biomedical applications. In this review, we embark on an overview of foundational topics that detail the design and fabrication of MCSPs by evaporation-induced emulsion and solvothermal techniques, and continue with a guideline for modification of MCSPs with inorganic oxides and organic polymers. Particular focus is then placed on the biomedical applications of modified MCSPs. Many examples illustrate the latest progress in design of MCSP-based microspheres for magnetic resonance imaging, targeted drug delivery, sensing, and harvesting of peptides/proteins. After these detailed accounts, the current challenges and future development of researches and applications are discussed as a conclusion to the review.

An accessible protocol for solid-phase extraction of N-linked glycopeptides through reductive amination by amine-functionalized magnetic nanoparticles

In light of the significance of glycosylation for wealthy biological events, it is important to prefractionate glycoproteins/glycopeptides from complex biological samples. Herein, we reported a novel protocol of solid-phase extraction of glycopeptides through a reductive amination reaction by employing the easily accessible 3-aminopropyltriethoxysilane (APTES)-functionalized magnetic nanoparticles. The amino groups from APTES, which were assembled onto the surface of the nanoparticles through a one-step silanization reaction, could conjugate with the aldehydes from oxidized glycopeptides and, therefore, completed the extraction. To the best of our knowledge, this is the first example of applying the reductive amination reaction into the isolation of glycopeptides. Due to the elimination of the desalting step, the detection limit of glycopeptides was improved by 2 orders of magnitude, compared to the traditional hydrazide chemistry-based solid phase extraction, while the extraction time was shortened to 4 h, suggesting the high sensitivity, specificity, and efficiency for the extraction of N-linked glycopeptides by this method. In the meantime, high selectivity toward glycoproteins was also observed in the separation of Ribonuclease B from the mixtures contaminated with bovine serum albumin. What's more, this technique required significantly less sample volume, as demonstrated in the successful mapping of glycosylation of human colorectal cancer serum with the sample volume as little as 5 μL. Because of all these attractive features, we believe that the innovative protocol proposed here will shed new light on the research of glycosylation profiling.