Immobilization of 2‑Deoxy‑d‑ribose-5-phosphate Aldolase in Polymeric Thin Films via the Langmuir–Schaefer Technique

A synthetic protocol for the fabrication of ultrathin polymeric films containing the enzyme 2-deoxy-d-ribose-5-phosphate aldolase from Escherichia coli (DERAEC) is presented. Ultrathin enzymatically active films are useful for applications in which only small quantities of active material are needed and at the same time quick response and contact times without diffusion limitation are wanted. We show how DERA as an exemplary enzyme can be immobilized in a thin polymer layer at the air–water interface and transferred to a suitable support by the Langmuir–Schaefer technique under full conservation of enzymatic activity. The polymer in use is a poly­(N-isopropylacrylamide-co-N-2-thiolactone acrylamide) (P­(NIPAAm-co-TlaAm)) statistical copolymer in which the thiolactone units serve a multitude of purposes including hydrophobization of the polymer, covalent binding of the enzyme and the support and finally cross-linking of the polymer matrix. The application of this type of polymer keeps the whole approach simple as additional cocomponents such as cross-linkers are avoided.