This chapter summarizes our work in the field of the production of magnetic metal-ceramic nanocomposites, starting from a zeolite precursor, and their use in biologic separations. We produced magnetic metal-ceramic nanocomposites as follows. We subjected to Fe2+ exchange commercial samples of zeolite A and X. Then, we thermally treated the obtained Fe-exchanged A and X zeolite samples at moderate temperatures (500–800 °C) for times up to 2 h, under a reducing atmosphere created by a flow of a gaseous mixture H2-Ar (H2 concentration 3% vol.). We fully characterized the final products of this process. We determined their total iron content and ζ-potential, we subjected them to X-ray powder diffraction (XRPD) analysis, we performed their quantitative phase determination by the Rietveld method, we characterized them by N2 adsorption at -196 °C, high resolution transmission electron microscopy (HRTEM), and from the magnetic point of view. This characterization revealed that the products of the previously described process are metal-ceramic nanocomposites, wherein magnetic nanoparticles of metallic iron (5–30 nm), sometimes together with some crystal of fayalite FeSiO4, are dispersed in a ceramic matrix, prevailingly composed by amorphous silica and alumina. Such ceramic matrix keeps a part of the porosity of the original zeolite structure. We used the magnetic adsorbents, obtained through the described procedure, in the biologic separation of i) Escherichia Coli DNA from crude cell lysate; ii) target gene factors V and RNASE, and bacterium Staphylococcus Aureus from human blood. We compared the results obtained in these biological separations by using our magnetic adsorbents with the results obtained by performing the same biological separation by using top ranking devices commercially available. As far as the separation of Escherichia Coli DNA from crude cell lysate is concerned, our magnetic adsorbent separated an Escherichia Coli DNA amount about 1.6 and 3 times higher than the commercial device. In the case of the separation of target gene factors V and RNASE, and bacterium Staphylococcus Aureus from human blood, we found slightly better results by using our magnetic adsorbent rather than the commercial device. In all the performed biologic separations, the magnetic properties of our adsorbents allowed a simple and expedite magnetic separation of the solid adsorbent from the liquid medium, wherein it was dispersed. Finally, we envisaged an industrial process aiming at the production of our magnetic adsorbents at low cost.

Biomedical Applications of Zeolite Based Materials

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发表日期：

2026年

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Michele Pansini,
Serena Esposito

摘要

This chapter summarizes our work in the field of the production of magnetic metal-ceramic nanocomposites, starting from a zeolite precursor, and their use in biologic separations. We produced magnetic metal-ceramic nanocomposites as follows. We subjected to Fe2+ exchange commercial samples of zeolite A and X. Then, we thermally treated the obtained Fe-exchanged A and X zeolite samples at moderate temperatures (500–800 °C) for times up to 2 h, under a reducing atmosphere created by a flow of a gaseous mixture H2-Ar (H2 concentration 3% vol.). We fully characterized the final products of this process. We determined their total iron content and ζ-potential, we subjected them to X-ray powder diffraction (XRPD) analysis, we performed their quantitative phase determination by the Rietveld method, we characterized them by N2 adsorption at -196 °C, high resolution transmission electron microscopy (HRTEM), and from the magnetic point of view. This characterization revealed that the products of the previously described process are metal-ceramic nanocomposites, wherein magnetic nanoparticles of metallic iron (5–30 nm), sometimes together with some crystal of fayalite FeSiO4, are dispersed in a ceramic matrix, prevailingly composed by amorphous silica and alumina. Such ceramic matrix keeps a part of the porosity of the original zeolite structure. We used the magnetic adsorbents, obtained through the described procedure, in the biologic separation of i) Escherichia Coli DNA from crude cell lysate; ii) target gene factors V and RNASE, and bacterium Staphylococcus Aureus from human blood. We compared the results obtained in these biological separations by using our magnetic adsorbents with the results obtained by performing the same biological separation by using top ranking devices commercially available. As far as the separation of Escherichia Coli DNA from crude cell lysate is concerned, our magnetic adsorbent separated an Escherichia Coli DNA amount about 1.6 and 3 times higher than the commercial device. In the case of the separation of target gene factors V and RNASE, and bacterium Staphylococcus Aureus from human blood, we found slightly better results by using our magnetic adsorbent rather than the commercial device. In all the performed biologic separations, the magnetic properties of our adsorbents allowed a simple and expedite magnetic separation of the solid adsorbent from the liquid medium, wherein it was dispersed. Finally, we envisaged an industrial process aiming at the production of our magnetic adsorbents at low cost.