Facile synthesis of hyperbranched magnetic nanomaterials for selective adsorption of proteins.

The separation and purification of proteins is an essential precondition for proteomics research because of the intricate matrix environment. Hence, a facile method has been developed to synthesize hyperbranched polyethyleneimine modified magnetic nanomaterials (Fe3O4-NH2-BPEI) with dendritic structure, unique electrostatic effect, and abundant functional groups for the selective adsorption of proteins which greatly avoids the drawbacks of time consumption and leakage of metal ions in traditional pre-treatment. The preparation conditions, physical and chemical properties, and adsorption performance of Fe3O4-NH2-BPEI have been fully studied. The obtained materials have stable crystal shape, adequate superparamagnetism, fast adsorption kinetics, high adsorption amount, and admirable reusability. In addition, the as-prepared Fe3O4-NH2-BPEI exhibits good selective adsorption ability for electronegative proteins in the neutral solution, exhibiting a potential value for special adsorption for proteins with different pI.

Preparation of Cu(2+)-mediated magnetic imprinted polymers for the selective sorption of bovine hemoglobin.

In this work, a novel Cu(2+)-mediated core-shell bovine hemoglobin imprinted superparamagnetic polymers were synthesized. First, carboxyl group directly-functionalized Fe3O4 nanoparticles were produced by a facile one-pot hydrothermal method. Next, copper ions were introduced to chelate with carboxyl groups and further bonded with template bovine hemoglobin as co-functional monomer. Then, functional monomers 3-aminopropyltriethoxylsilane and octyltrimethoxysilane were adopted to form the thin polymer layers. Finally, after removal of the templates, the imprinting shells with specific recognition cavities for bovine hemoglobin were obtained on Fe3O4 nanoparticles. The resultant molecularly imprinted polymers have high adsorption capacity and satisfactory selectivity for bovine hemoglobin with the help of copper ions. The obtained magnetic nanomaterials were characterized by transmission electron microscopy, Fourier-transform infrared spectra, X-ray diffraction, and vibrating sample magnetometer. The measurements demonstrated that the as-synthesized nanomaterials exhibited good dispersion, high crystallinity, and satisfactory superparamagnetic properties. The feasibility of this method was further confirmed by using the imprinted nanomaterials to specifically extract bovine hemoglobin from real bovine blood samples.

A highly-efficient imprinted magnetic nanoparticle for selective separation and detection of 17ß-estradiol in milk.

In this work, we prepared molecularly imprinted polymers (MIPs) combining surface molecular imprinting technique and magnetic separation for separation and determination of 17ß-estradiol (E2) from milk. During the synthesis process, the acryloyl chloride was specially used to graft double bonds on Fe3O4 nanoparticles and served as co-functional monomer cooperating with acrylamide. The morphology, structure property, and the best polymerization and adsorption conditions of the prepared magnetic nanoparticles were investigated in detail. The obtained nanomaterials displayed high adsorption capacity of 12.62mg/g, fast equilibrium time of 10min, and satisfactory selectivity for target molecule. What's more, the MIPs was successfully applied as sorbents to specifically separate and enrich E2 from milk with a relatively high recovery (88.9-92.1%), demonstrating the potential application of the MIPs as solid phase extractant for rapid, highly-efficient, and cost-effective sample analysis.

Novel polydopamine imprinting layers coated magnetic carbon nanotubes for specific separation of lysozyme from egg white.

Novel core-shell nanocomposites, consisting of magnetic carbon nanotubes (MCNTs) core surrounded by a thin polydopamine (PDA) imprinting shell for specific recognition of lysozyme (Lyz), were fabricated for the first time. The obtained products were characterized and the results showed that the PDA layer was successfully attached onto the surface of MCNTs and the corresponding thickness of imprinting layer was just about 10nm which could enable the template access the recognition cavities easily. The polymerization conditions and adsorption performance of the resultant nanomaterials were investigated in detail. The results indicated that the obtained imprinted polymers showed fast kinetic and high affinity towards Lyz and could be used to specifically separate Lyz from real egg white. In addition, the prepared materials had excellent stability and no obvious deterioration after five adsorption-regeneration cycles. Easy preparation, rapid separation, high binding capacity, and satisfactory selectivity for the template protein make this polymer attractive in biotechnology and biosensors.

Synthesis of magnetic dual-template molecularly imprinted nanoparticles for the specific removal of two high-abundance proteins simultaneously in blood plasma.

Novel core-shell dual-template molecularly imprinted superparamagnetic nanoparticles were synthesized using bovine hemoglobin and bovine serum albumin as the templates for the efficient depletion of these two high-abundance proteins from blood plasma for the first time. The preparation process combined surface imprinting technique and a two-step immobilized template strategy. The obtained polymers were fully characterized by transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and vibrating sample magnetometry. The results showed that the as-synthesized nanomaterials possessed homogeneous and thin imprinted shells with a thickness of about 5 nm, stable crystalline phase, and superparamagnetism. The binding performance of the imprinted polymers was investigated through a series of adsorption experiments, which indicated that the products had satisfactory recognition ability for bovine hemoglobin and bovine serum albumin. The resultant nanoparticles were also successfully applied to simultaneously selective removal of two proteins from a real bovine blood sample.

One-step preparation of magnetic imprinted nanoparticles adopting dopamine-cupric ion as a co-monomer for the specific recognition of bovine hemoglobin.

A novel magnetic core-shell polydopamine-cupric ion complex imprinted polymer was prepared in one-step through surface imprinting technology, which could specifically recognize bovine hemoglobin from the real blood samples. The polymerization conditions and adsorption performance of the resultant nanomaterials were investigated in detail. The results showed that the cupric ion played an important role in the recognition of template proteins. The saturating adsorption capacity of this kind of imprinted polymers was 2.23 times greater than those of imprinted polymers without cupric ion. The imprinting factor of the imprinted materials was as high as 4.23 for the template molecule. The selective separation bovine hemoglobin from the real blood sample is successfully applied. In addition, the prepared materials had excellent stability and no obvious deterioration after five adsorption-regeneration cycles. Easy preparation, rapid separation, high binding capacity and satisfactory selectivity for the template protein make this polymer attractive in the separation of high-abundance proteins.