Researchers from the Institute of Technical Biocatalysis, the Institute for Thermal Separation Processes and the Institute of Chemical Reaction Engineering, connected through the CRC 1615 SMART Reactors, have shared new results on the use of stimuli-responsive hydrogels as enzyme carriers. The project is carried out in association with the United Nations University Hub on Engineering to Face Climate Change at Hamburg University of Technology and the United Nations University Institute for Water, Environment and Health (UNU-INWEH).
Enzyme immobilisation on stimuli-responsive hydrogels provides a strategy to control biocatalytic activity under fluctuating process conditions. In Part A, formate dehydrogenase was immobilised on three hydrogel carriers: pH-responsive poly(2-hydroxyethyl methacrylate-co-itaconic acid), temperature-responsive poly(N-isopropylacrylamide) and dual-responsive poly(N-isopropylacrylamide-co-itaconic acid). The materials were characterised in terms of swelling behaviour, mechanical properties and morphology, and their immobilisation performance was evaluated across two carrier geometries, monoliths and particles, and two immobilisation techniques, adsorption and covalent binding.
Polymer chemistry was identified as the dominant factor controlling enzyme loading density, with the dual-responsive formulation achieving the highest loading despite moderate immobilisation yields. The responsive hydrogels therefore demonstrate strong potential as smart enzyme carriers, particularly in continuous-flow reactor designs, where improved substrate availability and increased convection can mitigate diffusion limitations and fully exploit the responsive properties of the immobilised enzyme systems.
Kayla Reata Dittmer, Kathrin Marina Eckert, Sherliana Setiawan, Patrick André Kißling, Daniel Ohde, Irina Smirnova, Andreas Liese (2026). Enzyme Immobilization on Stimuli-Responsive Hydrogels – Part A. Influence of Carrier Properties on Immobilization Efficiency and Catalytic Performance. Ind. Eng. Chem. Res. 65 (26).
