Behavior of glucose oxidase immobilized in various electropolymerized thin films

Abstract

Glucose oxidase was immobilized by electropolymerization into films of polyaniline, polyindole, polypyrrole, poly(o‐phenylediamine), and polyaniline crosslinked with p‐phenylenediamine. The kinetics and the behavior of the entrapped enzyme toward elevated temperature, organic solvent denaturation, and pH were investigated, along with the response of the films to electroactive species such as acetaminophen, ascorbate, cysteine, and uric acid. For most of the films, linearity to glucose extended from 7 to 10 mM. The poly(o‐phenylenediamine)/glucose oxidase film gave the best signal/noise ratio and polypyrrole/glucose oxidase film gave the most reproducible current responses. No significant shift of the optimum reaction pH (5.5), except for polypyrrole (5.0), was observed after immobilization of glucose oxidase in the various films. Enzymatic activity decreased rapidly when pH was raised above 7.5. Thermodeactivation studies at 55°, 60°, and 65°C have shown polypyrrole/and poly(o‐phenylediamine)/glucose oxidase films to be the most resistant enzymatic films. Poly(o‐phenylenediamine) films offered the best protection against glucose oxidase deactivation in hexane, chloroform, ether, THF, and acetonitrile when compared with the other electropolymerized films. All the enzymatic films exhibited permselection toward electroactive species. © 1996 John Wiley & Sons, Inc.

Biochips: non-conventional strategies for biosensing elements immobilization

“…On the model of the entrapment, oxidase enzymes were immobilized by electro-polymerization into conductive polymers films of polyaniline, polyindole, polypyrrole and poly(o-phenyldiamine) (52). The kinetic and the behavior of the entrapped enzyme toward temperature, solvent and pH were studied.…”

Electropreparation of (±)‐10‐camphorsulfonate‐doped poly(o‐phenylenediamine) in acetonitrile and its use in determination of glucose

“…Composite structures or materials including nonconducting polymers, like polyphenol and its derivatives, polyphenylenediamines and overoxidized polypyrrole could be used for amperometric biosensor design . Poly( o ‐phenylenediamine) (P o PD) films have been especially used in the preparation of amperometric enzyme electrode for glucose determination …”

Mixed matrix membranes : a new platform for enzymatic reactions

“…When in presence of a carrier with hydrophobic characteristics, the enzyme will adsorb on the surface, thereby changing its conformation. This type of adsorption can be difficult to handle, as the remaining activity can be enhanced [29][30][31][32][33] or reduced [34][35][36][37], depending on how the unfolding of the protein takes place. In situations where the active sites of the immobilized enzyme are exposed to the surrounding medium, the activity can be highly enhanced (figure 2.5I).…”

“…This suggests that GOx mainly retains configuration after immobilization in mixed matrix hollow-fibers (MMHF's). This is also in accordance to literature, where different maximums for GOx activity ranging from pH 5.0 to 7.0 are published [20,26,[32][33][34]. In order to better describe the behavior of immobilized GOx, the immobilized enzymatic activity is related to the total amount of adsorbed GOx, as displayed in figure 5.12.…”

“…More recently, MMM's have been developed with a porous polymer having functional particles embedded. These new structures may find applications in the field of biotechnology, as media for protein adsorption [32,33] and separation [34], blood purification [35,36] and enzyme concentration [37,38]. Figure 1.5 shows an example of a mixed matrix hollow-fiber.…”