Bio-organoclays based on phospholipids as immobilization hosts for biological species

A new type of hybrid biomaterials based on the clay minerals montmorillonite and sepiolite as well as phosphatidylcholine, acting as environment-friendly biomodifier, was prepared. The biohybrids were characterized by sampling of adsorption isotherms in different organic solvents. The results suggest bilayer formation both on the external sepiolite surface as well as in the intracrystalline space of the montmorillonite. The obtained supported lipid membranes were further investigated by X-ray diffraction, multinuclear solid state NMR, Fourier transformed IR spectroscopy and thermal analysis. From these results an adsorption model based on electrostatic interaction between the polar phospholipid headgroups and the silicate surface could be postulated. The versatility of bio-organoclays as immobilization host for biological species was demonstrated in a mycotoxin retention study.