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1.
A facile and effective approach to preparation of dual‐responsive magnetic core/shell composite microspheres is reported. The magnetite(Fe3O4)/poly(methacrylic acid) (PMAA) composite microspheres were synthesized through encapsulating γ‐methacryloxypropyltrimethoxysilane (MPS)‐modified magnetite colloid nanocrystal clusters (MCNCs) with crosslinked PMAA shell. First, the 200‐nm‐sized MCNCs were fabricated through solvothermal reaction, and then the MCNCs were modified with MPS to form active vinyl groups on the surface of MCNCs, and finally, a pH‐responsive shell of PMAA was coated onto the surface of MCNCs by distillation‐precipitation polymerization. The transmission electron microscopy (TEM) and vibrating sample magnetometer characterization showed that the obtained composite microspheres had well‐defined core/shell structure and high saturation magnetization value (35 emu/g). The experimental results indicated that the thickness and degree of crosslinking of PMAA shell could be well‐controlled. The pH‐induced change in size exhibited by the core/shell microspheres reflected the PMAA shell contained large amount of carboxyl groups. The carboxyl groups and high saturation magnetization make these microspheres have a great potential in biomolecule separation and drug carriers. Moreover, we also demonstrated that other magnetic polymeric microspheres, such as Fe3O4/PAA, Fe3O4/PAM, and Fe3O4/PNIPAM, could be synthesized by this approach. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011.  相似文献   

2.
《中国化学快报》2019,30(12):2181-2185
Investigations of glycosylated proteins or peptides and their related biological pathways provide new possibilities for illuminating the physiological and pathological mechanisms of glycosylation modification. However, open-ended and in-depth analysis of glycoproteomics is usually subjected to the low-abundance of glycopeptides, heterogeneous glycans, and a variety of interference molecules. In order to alleviate the influence of these obstacles, effective preconcentration of glycopeptides are indispensable. Here, we employed a hydrophilic interaction liquid chromatography (HILIC)-based method to universally capture glycopeptides. Glutathione modified magnetic nanoparticles (Fe3O4@Au-GSH) were synthesized through a simple process and exploited to enrich glycopeptides from complex samples. The prepared materials showed excellent ability to trap glycopeptides from standard glycoproteins digests, low detection limit (10 fmol/μL), and good selectivity (HRP:BSA = 1:100). These results indicated that glutathione-based magnetic nanoparticles synthesized in this work had great potential for glycopeptides enrichment.  相似文献   

3.
Hydrophilic interaction liquid chromatography(HILIC) has been recognized as an effective strategy for glycopeptide enrichment. Hydrophilic materials pave the way to solve the limit of low enrichment capacity and poor selectivity. The present study is the first attempt to combine chitosan(CS) and L-cysteine(L-Cys) to design a novel hydrophilic material focusing on glycopeptide enrichment. CS containing a large number of hydrophilic amino and hydroxyl groups has unique chemical properties, which m...  相似文献   

4.
Targeted drug delivery is a promising approach to overcome the limitations of classical chemotherapy. In this respect, Imatinib‐loaded chitosan‐modified magnetic nanoparticles were prepared as a pH sensitive system for targeted delivery of drug to tumor sites by applying a magnetic field. The proposed magnetic nanoparticles were prepared through modification of magnetic Fe3O4 nanoparticles with chitosan and Imatinib. The structural, morphological and physicochemical properties of the synthesized nanoparticles were determined by different analytical techniques including energy‐dispersive X‐ray spectroscopy (EDS), field emission scanning electron microscopy (FESEM), Fourier‐transform infrared (FTIR) spectroscopy, high resolution transmission electron microscopy (HR‐TEM), vibrating sample magnetometry (VSM), X‐ray diffraction (XRD) and X‐ray photoelectron spectroscopy (XPS). UV/visible spectrophotometry was used to measure the Imatinib contents. Thermal stability of the prepared particles was investigated and their efficiency of drug loading and release profile were evaluated. The results demonstrated that Fe3O4@CS acts as a pH responsive nanocarrier in releasing the loaded Imatinib molecules. Furthermore, the Fe3O4@CS/Imatinib nanoparticles displayed cytotoxic effect against MCF‐7 breast cancer cells. Results of this study can provide new insights in the development of pH responsive targeted drug delivery systems to overcome the side effects of conventional chemotherapy.  相似文献   

5.
《中国化学快报》2022,33(10):4695-4699
Both glycosylation and phosphorylation exert crucial rule in multitudinous biological processes. For in-depth profiling of glycosylation and phosphorylation, a magnetic metal oxide is effectively coupled with inherently hydrophilic mesoporous channels (denoted as Fe3O4@TiO2@mSiO2-TSG). Based on the mechanism of hydrophilic interaction liquid chromatography (HILIC) and metal oxide affinity chromatography (MOAC), the Fe3O4@TiO2@mSiO2-TSG nanomaterial shows high capacity for simultaneously enriching glycopeptides and phosphopeptides. With human saliva collected in successive four days as practical biological sample, endogenous glycopeptides and phosphopeptides are efficiently enriched. Further gene ontology analysis reveals that the identified endogenous glycopeptides and phosphopeptides participate in diverse molecular functions and biological processes. This strategy is anticipated to promote variation analysis of salivary post-translational modifications.  相似文献   

6.
黄倩  何蔓  陈贝贝  胡斌 《色谱》2014,32(10):1131-1137
制备了苯乙烯(St)和甲基丙烯酸(MAA)共聚物改性的磁性微球Fe3O4@P(St-co-MAA),并将其作为磁固相萃取吸附剂,建立了磁固相萃取(MSPE)-气相色谱(GC)-火焰光度检测(FPD)联用分析有机磷农药(OPPs)残留的新方法。以5种有机磷农药(二嗪农、甲基毒死蜱、杀螟硫磷、毒死蜱和喹硫磷)为目标分析物,考察并优化了吸附和解吸条件,确定了最佳实验条件。在最优的实验条件下,方法对5种OPPs的检出限(S/N=3)为0.013~0.305 μg/L,方法的相对标准偏差(RSD,n=7)为3.1%~8.8%,富集倍数为406~951,线性范围达3个数量级。将该方法应用于新鲜番茄汁、草莓汁样品中的OPPs残留分析,加标回收率为85.4%~118.9%。该方法具有检出限低、分析速度快、富集倍数高等优点,为有机磷农药的残留分析提供了新的技术平台。  相似文献   

7.
In the present study, ionic liquid (IL)‐modified Fe3O4 magnetic nanoparticles (Fe3O4) were synthesized by the thiol‐ene click reaction for magnetic solid‐phase extraction (MSPE) of polycyclic aromatic hydrocarbons (PAHs) in water and smoked meat samples. An IL 1‐vinyl‐3‐butylimidazolium bromide was firstly synthesized, and then immobilized on the surface of thiol group‐functionalized Fe3O4 via a thiol‐ene click reaction. The as‐synthesized Fe3O4@ILs were characterized using Fourier transform infrared spectroscopy, X‐ray diffraction, and transmission electron microscopy. Various parameters (including the amount of adsorbent, extraction time, sample volume, and desorption conditions) affecting MSPE were optimized. Under the optimum conditions, the limits of detection of four PAHs in the range of 0.6–7.2 ng/L were obtained using high‐performance liquid chromatography–ultraviolet detection. The accuracy of the method was assessed by recovery measurements on spiked real samples and good recovery of 80–108% with relative standard deviations lower than 8.16% was achieved. The enrichment factors ranging from 699 to 858 were obtained for the analytes. This result indicated that the proposed method had great potential for sample preparation.  相似文献   

8.
A novel magnetic adsorbent Fe3O4/reduced graphene oxide‐carbon nanotubes, was prepared by one‐pot solvothermal synthesis method. It was characterized by scanning electron microscopy, X‐ray powder diffraction and vibrating sample magnetometry. The diameter of Fe3O4 microparticles was about 350 nm, which were covered by carbon nanotubes and reduced graphene oxide sheets, while carbon nanotubes inserted between the reduced graphene oxide sheets effectively prevented their aggregation. The composite had large surface area and good magnetic property, suiting for magnetic solid‐phase extraction and the determination of sulfonamides, by coupling with high‐performance liquid chromatography. Under the optimized conditions (including extraction time, amount of adsorbent, solution pH, ionic strength and desorption conditions), a good linear was achieved in the concentration range of 5–500 μg/L and the low limits of detection and low limits of quantification were 0.35–1.32 and 1.16–4.40 μg/L, respectively. The enrichment factors were estimated to be 24.72 to 30.15 fold. The proposed method was applied for the detection of sulfonamides in milk sample and the recoveries were 88.4–105.9%, with relative standard deviations of 0.74–5.38%.  相似文献   

9.
Polydopamine‐coated Fe3O4 magnetic nanoparticles synthesized through a facile solvothermal reaction and the self‐polymerization of dopamine have been employed as a magnetic solid‐phase extraction sorbent to enrich four phenolic compounds, bisphenol A, tetrabromobisphenol A, (S)‐1,1′‐bi‐2‐naphthol and 2,4,6‐tribromophenol, from environmental waters followed by high‐performance liquid chromatographic detection. Various parameters of the extraction were optimized, including the pH of the sample matrix, the amount of polydopamine‐coated Fe3O4 sorbent, the adsorption time, the enrichment factor of analytes, the elution solvent, and the reusability of the nanoparticles sorbent. The recoveries of these phenols in spiked water samples were 62.0–112.0% with relative standard deviations of 0.8–7.7%, indicating the good reliability of the magnetic solid‐phase extraction with high‐performance liquid chromatography method. In addition, the extraction characteristics of the magnetic polydopamine‐coated Fe3O4 nanoparticles were elucidated comprehensively. It is found that there are hydrophobic, π–π stacking and hydrogen bonding interactions between phenols and more dispersible polydopamine‐coated Fe3O4 in water, among which hydrophobic interaction dominates the magnetic solid‐phase extraction performance.  相似文献   

10.
A new type of metal-oxide-coated magnetic nanoparticles (NPs)—tantalum-oxide-coated magnetic iron oxide (Fe3O4@Ta2O5) NPs—which are used as affinity probes for selectively trapping phosphopeptides from complex samples, is demonstrated in this study. In this approach, phosphopeptide enrichment was achieved by incubating the NPs with sample solutions under microwave heating within 1 min. The NP–target species conjugates were readily isolated from samples by magnetic separation followed by matrix-assisted laser desorption/ionization (MALDI) mass spectrometric analysis. When using human serum as the sample, phosphorylated fibrinopeptide-A-derived ions are the only ions observed in the MALDI mass spectra after enrichment by the Fe3O4@Ta2O5 NPs. Furthermore, only phosphopeptides appear in the MALDI mass spectra after using the affinity probes to selectively trap target species from the tryptic digest of a cell lysate and milk sample. The results demonstrated that the Fe3O4@Ta2O5 NPs have the capability of selectively trapping phosphorylated peptides from complex samples. The detection limit of this approach for a phosphopeptide (FQpSEEQQQTEDELQDK) was ~10 fmol. Figure For the first time, tantalum oxide-coated magnetic iron oxide (Fe3O4@Ta2O5) NPs were demonstrated as suitable affinity-probes for selectively trapping phosphopeptides from complex samples. To shorten the analysis time, phosphopeptide enrichment was achieved by incubating the NPs with sample solutions under microwave-heating within 1 min. MALDI MS was employed for characterization of the species trapped by the NPs.  相似文献   

11.
In this study, a green protocol for supporting CuO nanoparticles over chitosan-modified amino-magnetic nanoparticles is described. The physicochemical and morphological properties of the desired nanocomposite assessed by various techniques like ICP, FT-IR, FE-SEM, EDX, TEM, XRD and VSM. In the oncological part of the recent study, the Cu(NO3)2, Fe3O4, and Fe3O4-NH2@CS/CuO nanocomposite cell viability was very low against human gastric cancer cell lines i.e. MKN45, AGS, and KATO III and human colorectal carcinoma cell lines i.e. HT-29, HCT 116, HCT-8 [HRT-18], and Ramos.2G6.4C10. The IC50 of Fe3O4-NH2@CS/CuO nanocomposite against MKN45, AGS, KATO III, HT-29, HCT 116, HCT-8 [HRT-18], and Ramos.2G6.4C10 cell lines were 517, 525, 544, 282, 214, 420, and 477 µg/mL, respectively. Thereby, the best anti-gastro-duodenal cancers findings of our Fe3O4-NH2@CS/CuO nanocomposite was seen in the HCT 116 cell line case.  相似文献   

12.
ABSTRACT

This study describes a new magnetic solid-phase extraction (MSPE) technique based on Fe3O4/graphene oxide-soluble eggshell membrane protein (Fe3O4/GO-SEP) for accurate measurement of malachite green (MG) residue in various water samples residues by UV-Vis spectroscopy. The morphology of the prepared adsorbent has been studied by scanning electron microscopy and atomic force microscopy in details. Parameters affecting the MSPE were optimised and determined with UV-Vis spectrophotometry thoroughly. Under the optimised extraction circumstances, the introduced method represented a wide linearity over the concentration of 0.5–250 ng mL?1, a high enrichment factor of 83.3 and low detection limit of 0.2 ng mL?1. The prepared Fe3O4/GO-SEP was successfully used for preconcentration and determination of MG in river and fish farming water samples with suitable precision and accuracy.  相似文献   

13.
Monodisperse magnetic surface molecularly imprinted polymers (M-MIPs) with a specificity for lincomycin hydrochloride (LIN) were successfully prepared using surface-initiated atom transfer radical polymerization on the monodisperse magnetic polymer (vinylbenzylchloride/divinylbenzene) (Fe3O4/PVBC/DVB) with LIN as a template molecule and 4-vinyl pyridine as the functional monomer. The Fe3O4 magnetic nanoparticles embedded itself in the micropores of polymer (PVBC/DVB) by reversibly swelling adsorption method in which the pores of the polymer are swollen by the solvent, and then the Fe3O4 magnetic nanoparticles enter the pores, and as the solvent evaporates the pores of the polymer back to their original size, and Fe3O4 magnetic nanoparticles are left in the pores. The composition and magnetic properties of the polymer were characterized using scanning elemental microscopy analysis, X-ray diffraction, Surface element analysis and vibrating sample magnetometer analysis. The results of this study showed that the M-MIPs had good specific recognition ability for LIN. The imprinting factor is 3.72. The specific recognition capability of the polymers was affirmed by high performance liquid chromatography analysis. The spiked recovery was 94.3%–98.2% with RSD ≤ 3.7%, and the minimum detection limit is 15.0?ng/g (S/N?=?3) indicating that this material has application value in the pretreatment of complex samples.  相似文献   

14.
As a low molecular weight protein with the ability of binding metal ions and high inducibility, metallothionein (MT) is often regarded as an important biomarker for assessment of heavy metal pollution in water environment. In the light of that the traditional process of enrichment and identification is time-consuming and complicated, we prepared a core-shell nanoparticle, gold-coated iron oxide nanoparticles (Fe3O4@Au NPs) herein. It possessed the advantages of fast response to magnetic fields and optical properties attributing to Fe3O4 and Au nanoparticles, respectively. The Fe3O4@Au nanoparticles could be used to enrich MT simply through Au–S interaction, and the purified proteins were determined by matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF/MS). The results showed that the Fe3O4@Au nanoparticles could directly enrich MT from complex solutions and the detection limit could be as low as 10 fg mL?1.  相似文献   

15.
Rapid and selective enrichment of phosphopeptides from complex biological samples is essential and challenging in phosphorylated proteomics. In this work, for the first time, niobium ions were directly immobilized on the surface of polydopamine-coated magnetic microspheres through a facile and effective synthetic route. The Fe3O4@polydopamine-Nb5+ (denoted as Fe3O4@PD-Nb5+) microspheres possess merits of high hydrophilicity and good biological compatibility, and demonstrated low limit of detection (2 fmol). The selectivity was also basically satisfactory (β-casein:BSA = 1:500) to capture phosphopeptides. They were also successfully applied for enrichment of phosphopeptides from real biological samples such as human serum and nonfat milk. Compared with Fe3O4@PD-Ti4+ microspheres, the Fe3O4@PD-Nb5+ microspheres exhibit superior selectivity to multi-phosphorylated peptides, and thus may be complementary to the conventional IMAC materials.  相似文献   

16.
This work describes a magnetic Fe3O4/graphene oxide (GO)-based solid-phase extraction (MSPE) technique for high performance liquid chromatography (HPLC) detection of malachite green (MG) and crystal violet (CV) in environmental water samples. Fe3O4/ GO magnetic nanoparticles were synthesised by a chemical co-precipitation method and characterised by scanning electron micrograph, transmission electron microscope, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and surface area analyser. The prepared Fe3O4/GO magnetic nanoparticles were used as the adsorbents of MSPE for MG and CV. By coupling with HPLC, a sensitive and cost-effective method for simultaneous determination of MG and CV was developed. The important parameters including the amount of Fe3O4/GO, pH of the sample solution, extraction time, salt effect, the type and volume of desorption solvent were investigated in detail. Under optimised conditions, the calibration curves were linear in the concentration range of 0.5–200 μg L?1, and the limits of detection were 0.091 and 0.12 μg L?1 for MG and CV, respectively. Finally, the established MSPE-HPLC method was successfully applied to determine MG and CV in environmental water samples with the recoveries ranging from 91.5% to116.7%.  相似文献   

17.
For the first time, a magnetic solid‐phase extraction with high‐performance liquid chromatography detection method using Zr functionalized Fe3O4 magnetic material to enrich ribavirin was successfully established. Zr components that modified in Fe3O4 nanoparticles via a simple one‐step hydrothermal method was selected in this work to specifically capture ribavirin by the strong chemical bonding between Zr components of Zr functionalized Fe3O4 magnetic material and cis‐hydroxyl of ribavirin, which was confirmed by pseudo‐second‐order kinetic model. And Fe3O4 components were selected in this work to achieve simple operation. Under the optimal experimental conditions, proposed magnetic solid‐phase extraction with high‐performance liquid chromatography detection method along with Zr functionalized Fe3O4 magnetic material offered a wide range linearity at 10–200 µg/L with correlation coefficient of 0.9978 with low detection limit of 2.68 µg/L for ribavirin. The relative standard deviations obtained from nine parallel extractions of 100 µg/L ribavirin were 4.41% and revealed good repeatability. This established method was successfully applied to detect real samples including chicken liver, egg, and shrimp with satisfactory recoveries of 74.13–92.9%.  相似文献   

18.
Glycoproteins are useful biomarkers and therapeutic targets for a number of diseases, including infections and cancer. However, identification and isolation of low‐abundant glycoproteins remains a significant challenge that limits their application. Thus, methods of specific and selective glycoprotein enrichment are required. In this study, novel phenylboronic acid functionalized magnetic microspheres were successfully synthesized. Fe3O4 microspheres were synthesized by using a hydrothermal method and were coated with tetraethyl orthosilicate using an ultrasonic method to form a core‐shell structure. Compared to the conventional mechanical stirring for 12 h, the ultrasonic method saved about 7 h in processing time, and the home‐made magnetic microspheres had better dispersibility and homogeneity. Subsequently, the magnetic microspheres were modified by addition of an amino group and a carboxyl group, in sequence. Finally, 3‐aminophenylboronic acid, as the functional monomer, was linked to the magnetic microspheres for capturing glycoprotein/glycopeptides. The results of this study indicate that phenylboronic acid functionalized magnetic microspheres show excellent adsorption performance toward glycoprotein/glycopeptides. The maximum absorbing capacity of the microspheres for fetuin was 108 mg/g, and the enrichment efficiency reached 89.7%, indicating their potential to separate and enrich glycoproteins from the complex biological samples.  相似文献   

19.
Shuang Qiu 《Talanta》2010,81(3):819-2153
A pseudo-homogeneous immunoextraction method based on gold-coated magnetic nanoparticles (MNPs) for the specific extraction and quantitative analysis of epitestosterone (17α-hydroxy-4-androsten-3-one, abbreviated as “ET”) from human urine samples by high-performance liquid chromatography (HPLC) has been developed. Half-IgG of anti-ET monoclonal antibodies were covalently immobilized onto (Fe3O4)core-Aushell (Fe3O4@Au) MNPs. An external magnetic field was applied to collect the MNPs which were then rinsed with distilled water followed by elution with absolute methanol to obtain ET as the analyte. The obtained extraction solution was analyzed by HPLC with UV detection (244 nm) within 12 min. The standard calibration curve for ET showed good linearity in the range of 20-200 ng mL−1 in phosphate-buffered saline (PBS) solutions with acceptable accuracy and precision. Limit of detection for ET was 0.06 ng mL−1 due to an enrichment factor of 100-fold was achieved. The results obtained by the present method for spiked human urine samples were in agreement with those from indirect competitive enzyme-linked immunoadsorbent assays (ELISAs). The antibody-conjugated Fe3O4@Au MNPs are novel materials for immunoaffinity extraction. Compared with the conventional technique using immunoaffinity column, the method described here for sample pretreatment was fast, highly specific, and easy to operate.  相似文献   

20.
We present a facile strategy to prepare the molecularly imprinted polymers layer on the surface of Fe3O4 nanoparticles with core‐shell structure via sol–gel condensation for recognition and enrichment of triclosan. The Fe3O4 nanoparticles were first synthesized by a solvothermal method. Then, template triclosan was self‐assembled with the functional monomer 3‐aminopropyltriethoxysilane on the silica‐coated Fe3O4 nanoparticles in the presence of ethanol and water. Finally, the molecularly imprinted polymers were formed on the surface of silica‐coated Fe3O4 nanoparticles to obtain the product. The morphology, magnetic susceptibility, adsorption, and recognition property of magnetic molecularly imprinted polymers were characterized using transmission electron microscopy, Fourier transform infrared spectroscopy, X‐ray diffractometry, vibrating sample magnetometry, and re‐binding experiments. The magnetic molecularly imprinted polymers showed binding sites with good accessibility, fast adsorption rate, and high adsorption capacity (218.34 μg/g) to triclosan. The selectivity of magnetic molecularly imprinted polymers was evaluated by the rebinding capability of triclosan and two other structural analogues (phenol and p‐chlorophenol) in a mixed solution and good selectivity with an imprinting factor of 2.46 was obtained. The application of triclosan removal in environmental samples was demonstrated.  相似文献   

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