Preparation of monodisperse magnetic polystyrene microspheres and its surface chemical modification

Liu, Gang; Guan, Yong; Ge, Ying; Xie, Li

doi:10.1002/app.33495

Cited by 13 publications

(5 citation statements)

References 50 publications

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“…In this work, to enhance the stability of PGA on supports, ILs were used to modify the surface of supports. Magnetic silica nanoparticles (Fe 3 O 4 /SiO 2 ) composed of an inner magnetic Fe 3 O 4 core and an outer silica shell were chosen as a support because of their special features and wide application fields. − Silane group-functionalized ILs with different anions (Cl – , BF 4 – , PF 6 – , Tf 2 N – ) were synthesized, and were used to modify the Fe 3 O 4 /SiO 2 particles. The enzyme loading, immobilized yield, and stability of ImPGA were studied.…”

Section: Introductionmentioning

confidence: 99%

Improving the Stability of Immobilized Penicillin G Acylase via the Modification of Supports With Ionic Liquids

Zhou

Yang

et al. 2012

Ind. Eng. Chem. Res.

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With the aim of improving the stability of penicillin G acylase (PGA), functional ionic liquids (ILs) were used to modify the surface chemistry of the supports on which they were physically adsorbed. Four kinds of ILsspecifically, 1-methyl-3-(triethoxysilylpropyl)-imidazolium salts, with Cl − , BF 4 − , PF 6 − , and Tf 2 N − as the anions (IL-Cl − , BF 4 − , PF 6 − , and Tf 2 N − , respectively)were used to tune the hydrophilic or hydrophobic properties of the ILs. The synthesized ILs were first immobilized on magnetic silica nanoparticles (Fe 3 O 4 /SiO 2 ), and the composite material (Fe 3 O 4 /SiO 2 −IL) was then applied to immobilize PGA via physical adsorption. The amount of protein loading, the specific activity, the immobilization yield, and the stability of immobilized PGA were investigated to evaluate the effects of the ILs on the PGA immobilization. The results showed that PGA immobilized on Fe 3 O 4 /SiO 2 −ILs was more stable than that immobilized on Fe 3 O 4 /SiO 2 with no IL modification. Among the four kinds of ILs tested, the hydrophilic ILs (IL-Cl − , and IL-BF 4 − ) were superior to the hydrophobic ones (IL-PF 6 − , and IL-Tf 2 N − ) for PGA immobilization. The reusability of the immobilized PGA on Fe 3 O 4 /SiO 2 −IL (BF 4 −) was evaluated; a high residual activity (70% of the initial activity) was observed after 9 consecutive operation cycles under the experimental conditions. This activity was 1.8 times higher than that of immobilized PGA on naked Fe 3 O 4 /SiO 2 (40%).

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Section: Introductionmentioning

confidence: 99%

Improving the Stability of Immobilized Penicillin G Acylase via the Modification of Supports With Ionic Liquids

Zhou

Yang

et al. 2012

Ind. Eng. Chem. Res.

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“…The number-average diameter, D n , was used to characterize the average sizes of the samples. The polydispersity index, PDI = D w / D n (where D w is the weight-average diameter), was used to evaluate the size distribution. , The formula of these three parameters can be expressed as follows: D normaln = ∑ i = 1 n d i N D normalw = ∑ i = 1 n d i 4 ∑ i = 1 n d i 3 PDI = D normalw D normaln where N is the total number of selected particles and d i is the diameter of the i particle.…”

Section: Methodsmentioning

confidence: 99%

Immobilizing Penicillin G Acylase Using Silica-Supported Ionic Liquids: The Effects of Ionic Liquid Loadings

Zhou

Yang

et al. 2012

Ind. Eng. Chem. Res.

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The supported ionic liquids (SILs) were prepared via immobilizing silane-functionalized ionic liquids (IL) onto the monodispersive silica nanoparticles, and the composite material was then applied in the immobilization of penicillin G acylase (PGA, EC 3.5.1.11), an important industrial enzyme for the production of semisynthetic antibiotics. This was a novel approach of immobilizing PGA proposed in our previous report, in which we had studied the effects of IL types on the performance of this novel support. Here, we focused on the effects of IL loading on the properties of the SILs and their performance in PGA immobilization. The effects of silica sizes and routes of preparing SILs (the solvent route and the sol–gel route) on IL loading were investigated. The results showed that (1) the IL loading could be tuned efficiently by changing the silica sizes. (2) As compared with the solvent route, the sol–gel route is more simple, time-saving, and ecofriendly in operation. What's more, it has a higher IL loading. Among the factors affecting the IL loading, the reaction time was the most feasible factor to control to tune the IL loading, as compared with the temperature and the dosage of ILs. (3) With the increase of IL loading, the surface ζ-potential of silicas changed from negative to positive, and the isoelectronic point (IEP) increased accordingly, which caused the decrease of the protein loading but the increase of apparent and specific activity. A reusability experiment showed that the sol–gel 1 sample maintained approximately 55% of the initial activity even after 10 consecutive operation cycles under the experimental conditions. This activity was 3.7 times higher than that of the sol–gel 2 sample.

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“…For the use of microspheres in planar immunoassay, they must have sufficient magnetic properties, for example, due to the high content of magnetite [34]. This condition is due to the need to immobilize the microspheres in the cell using a magnet for analysis [35].…”

Section: Magnetic Propertiesmentioning

confidence: 99%

Synthesis and experimental study of liquid dispersions of magnetic fluorescent polystyrene microspheres

Shalaev

Bondina

Sankova

et al. 2021

kcmf

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Multiplex microsphere-based immunofluorescence assay is a reliable, accurate, and highly sensitive method for the detection of various biomolecules. However, for the moment, the wide application of the method in clinical practice is prevented by the high cost of reagents for analysis - magnetic spectrally encoded microspheres. Therefore, an urgent task is the development of new methods for the synthesis of microspheres with the required properties. The aim of this study was the creation of new magnetic fluorescent microspheres suitable for use in multiplex immunoassay.Samples of magnetic fluorescent polystyrene microspheres were synthesized by dispersion polymerization and two-stage swelling methods. Experimental studies of geometric parameters, fluorescence, magnetic properties of the synthesized microspheres have been carried out.The results of the studies have shown that microspheres synthesized by dispersion polymerization are promising for the use in immunofluorescence analysis. The obtained results can be used for the development of new diagnostic multiplex test systems based on spectrally encoded microspheres.

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Preparation of monodisperse magnetic polystyrene microspheres and its surface chemical modification

Cited by 13 publications

References 50 publications

Improving the Stability of Immobilized Penicillin G Acylase via the Modification of Supports With Ionic Liquids

Improving the Stability of Immobilized Penicillin G Acylase via the Modification of Supports With Ionic Liquids

Immobilizing Penicillin G Acylase Using Silica-Supported Ionic Liquids: The Effects of Ionic Liquid Loadings

Synthesis and experimental study of liquid dispersions of magnetic fluorescent polystyrene microspheres

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