Direct electrochemical and electrocatalytic properties of heme protein immobilized on ionic liquid-clay-nanoparticle-composite films

A novel ionic liquid and clay nanoparticle composite film coated on the surface of a pyrolytic graphite (PG) electrode was fabricated and characterized by means of scanning electron microscopy (SEM), UV-Vis absorption, cyclic voltammetry (CV) and square wave voltammetry (SWV) techniques. The composite film was used to immobilize heme protein (hemoglobin). Electrochemically catalytic reduction of oxygen, trichloroacetic acid, nitrite, and hydrogen peroxide over the immobilized enzyme was measured. Experimental data showed that the composite film can provide a favorable microenvironment for the protein to directly transfer electrons, showing that such immobilized protein system can be potential biosensors.