Département de chimie moléculaire

The direct electron transfer between Hb and the underlying glassy carbon electrode (GCE) can be readily achieved via a high biocompatible composite system based on biopolymer chitosan (CHT) and inorg. CaCO3 nanoparticles (nano-CaCO3). Cyclic voltammetry of Hb-CHT/nano-CaCO3/GCE showed a pair of stable and quasi-reversible peaks for HbFe(III)/Fe(II) redox couple in pH 7.0 buffer. The electrochem. reaction of Hb immobilized in CHT/nano-CaCO3 composite matrix exhibited a surface-controlled process accompanied by electron and proton transfer. The electron transfer rate const. was estd. to be 1.8 s-1. This modified electrode showed a high thermal stability up to 60°. The apparent Michaelis-Menten const. was calcd. to be 7.5 × 10-4 M, indicating a high catalytic activity of the immobilized Hb toward H2O2. The interaction between Hb and this nano-hybrid material was also investigated using FT-IR and UV-vis spectroscopy, indicating that Hb retained its native structure in this hybrid matrix. [on SciFinder(R)]