Immobilized enzymes – valuable tools for the indication of temperature events

Abstract

The enzymes trypsin and urease were covalently tethered to cellulose to utilize their ability to produce colored products as a consequence of enzymatic activity. Therefore, cellulose had to be chemically modified first in order to generate appropriate chemical functionalities. Different approaches including periodate supported oxidation followed by immobilization via reductive amination, insertion of a reactive polymer interface, and cross-linking inside the cellulose matrix were utilized for the immobilization. The success of immobilization was assessed by the quantification of surface-bound protein as well as by recording of enzymatic activities under different conditions. The enzymatic activity of trypsin and urease was maintained best when a hydrophilic intermediate polymer layer was used for immobilization. The applicability of immobilized enzymes as temperature indicators was demonstrated using cross-linked urease.

Keywords::

• Cellulose
• immobilization
• trypsin
• urease
• reactive polymer
• temperature label

Acknowledgments

The authors thank the German Federal Ministry of Economics and Technology (grant no. KF2088002PR8: “Intelligente Etiketten zur Temp eratur-Zeit-Erkennung”) for financial support. Furthermore, we thank Prof. F. Weidhase, University of Applied Sciences Senftenberg, Germany, for the good cooperation within the project. The contribution of Christin Dittmer to carrier preparation and protein quantification is gratefully acknowledged.

Declaration of interest: The authors report no declarations of interest. The authors alone are responsible for the content and writing of the paper.