Soluble and film-forming cellulose derivatives with redox- chromogenic and enzyme immobilizing 1,4-phenylenediamine groups

Abstract

Cellulose architectures with redox-chromogenic properties and anchor groups for the immobilization of biomolecules have been prepared by reaction of p-toluenesulfonic acid esters of cellulose (tosylcellulose, DS 2.3) with 1,4-phenylenediamine (PDA) in dimethyl sulfoxide (DMSO) solution at 100°C. The degree of substitution (DS) of the PDA groups and remaining p-toluenesulfonate (tosylate) groups, and thus the properties of the 6-deoxy-6-(4-aminophenyl)amino-2(3)-O-tosylcellulose (PDA cellulose) formed, can be adjusted by varying the PDA molar equivalents and the reaction time. Most of PDA celluloses are soluble in DMSO and N,N-dimethylacetamide (DMA) and form transparent films. The redox-chromogenic properties of PDA cellulose have been demonstrated by oxidation of the PDA groups with H2O2 to the corresponding diimine (λmax = 480 nm) and by oxidative coupling with phenol to the corresponding indophenol (λmax = 595 nm). The suitability of the PDA units as reactive anchor groups was shown by the immobilization of enzymes like glucose oxidase, peroxidase, and lactate oxidase. The highest enzyme activity achieved for peroxidase immobilized with glutardialdehyde on a PDA cellulose film was 0.165 U/cm2.