(German title: Application of superparamagnetic particles in analytics and bioprocess engineering (BIOMAG))

In a cooperation between the Chair of Bioprocess Engineering and the Department of Biophysics at TU Kaiserslautern and the Department of Process Engineering (Environmental Campus Birkenfeld, Trier University of Applied Sciences), work is being carried out on the visualization of particles, their coating with biomolecules and the development of magnetic retention devices. The bioprocess engineering department uses precipitation and microemulsion methods to visualize particles. Particles with superparamagnetic magnetite inclusions in a wide size range can be synthesized from silicate, polyvinyl alcohol and agarose matrices, among others. Nanoparticles are synthesized at the Institute of Biophysics. For this purpose, a core of magnetite is produced, which is encased in an outer gold shell in a second step (core-shell particles). The shell offers protection against corrosion of the magnetite core on the one hand and the possibility of direct protein binding on the surface on the other. The particles have an average diameter of 76 nm.

The particles are functionalized with binding groups, such as amino or epoxy groups, during or after production. Techniques for covalent binding and cross-linking of proteins, and enzymes in particular, are available for the biotechnological functionalization of surfaces. The focus of research here is on optimizing binding with regard to enzyme activity and storage stability of the immobilizates.

The magnetizable particles are used and separated in complex material mixtures, such as fermentation broths, lignocellulose hydrolysates or whey concentrates. Recovery from these systems containing solids is carried out using a high gradient magnetic separator (HGMS). The geometry of the separation chamber is optimized using finite element modelling (FEM), taking into account the magnetic field and flow characteristics during the separations.