DIRECT ELECTROCHEMISTRY OF MEMBRANE-ENTRAPPED HORSERADISH-PEROXIDASE - PART I - A VOLTAMMETRIC AND SPECTROSCOPIC STUDY

This paper reports the electrochemical behaviour, relative to the Fe(I II)-Fe(II) conversion, of horseradish peroxidase (HRP) entrapped withi n a solid matrix, at a pyrolytic graphite electrode. The results indic ate that (i) immobilization enhances the electron exchange between the protein and the electrode surface; (ii) reversible electron transfer (eT) is achieved within a wide pH range (pH 3.0-12.0) even in the abse nce of mediators, (ii) the embedded protein shows native-like structur al properties and increased stability. The results obtained may be of potential value, since they represent a first step for engineering a n ovel 'solid-state' electrode system, of importance for basic and appli ed biochemistry. (C) 1998 Elsevier Science S.A.