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Magnetic particles (MNPs) offer attractive possibilities in biotechnology. MNPs can get close to a target biological entity, as their controllable sizes range from a few nanometres up to tens of nanometres, and their surface can be modified to add affinity and specificity towards desired molecules. Additionally, they can be manipulated by an external magnetic field gradient. In this work, the study of ferric oxide (Fe3O4) MNPs with different coating agents was conducted, particularly in terms of strategies for antibody attachment at the surfaces (covalent and physical adsorption) and the effects of blocking buffer composition and incubation times on the specific and non-specific interactions observed. The considered biological model system consisted of a coating antibody (goat IgG), bovine serum albumin (BSA) as blocking agent, and a complementary antibody labelled with FITC (anti-goat IgG). The detection of antibody binding was followed by fluorescence microscopy and the intensity of the signals quantified. The ratio between the mean grey values of negative and positive controls, as well as the maximum intensity attainable in positive controls, were considered in the evaluation of the assays efficiency. The covalent immobilization of the coating antibody was more successful as opposed to protein adsorption. For covalent immobilization, silica-coated MNPs, a 5% (w/v) concentration of BSA in the blocking buffer and incubation times of 1 h produced the best results in terms of assay sensitivity. However, when conducting the assay for incubation periods of 10 min, the fluorescence signal was reduced by 44% but the assay specificity was maintained.

We present molecular simulations of gases in mesoporous MOF MIL-100(Fe) impregnated with ionic liquidsAdsorption of pure carbon dioxide, methane, nitrogen, and typical mixtures found in flue gases and natural gas are studied. Increases in CO 2 adsorption, sitting, and selectivity were investigated to provide an impregnation alternative in a stable material that could be experimentally successful. The presence of ionic liquids, in particular [Bmim + ][SCN − ], increases CO 2 uptake within the pressure range up to 2000 kPa, which is unprecedented for impregnated MOF structures. We found that the impregnation of the mesoporous MOF structure doubles CO 2 adsorbed concentration and selectivities (CO 2 /CH 4 and CO 2 /N 2 ) at ambient temperature and low pressure range (<100 kPa). These results provide evidence that IL impregnation of mesoporous MOFs may render them unique characteristics that are likely to be useful for CO 2 capture.

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Despite the great industrial importance of zeolite LTA, there is still a gap in characterization methods, based on adsorption related to hindered diffusion of standard probe gases, such as N2 and Ar. LTA has a three-dimensional porous structure with a high degree of symmetry; however, variations in the location of cations, notably S2 and S3 sites, lead to different energy levels in supercages. Herein, we propose to extend the pore type distribution (PTD) methodology, recently applied for metal–organic frameworks, to zeolite materials. As an application example, we selected Na-LTA (4A) zeolite. Structural properties accessed by molecular simulation methods combined with experimental adsorption isotherms of CO2 at 273 K determine the individual contribution of supercages, with different energy levels, to the total adsorption uptake. Using eight local isotherms from the supercages, we developed a kernel that estimates the most likely energy distribution levels among supercages from the best fits of experimental isotherms. The method was applied in detail for LTA samples synthesized in laboratory and supplied by an industrial manufacturer. As an extension of the approach, we also analyze the use of the average local isotherm in the determination of imperfections found in the synthesis of LTA from unconventional raw materials or its deactivation in industrial processes. The proposed methodology generates detailed and relevant information not accessed by existing methods and allows the use of adsorption to characterize this class of very small pore sieves.

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