Entrapment of enzyme within organic and inorganic materials for biosensor applications: Comparative study

In order to determine the best kind of matrix that enables preservation of the enzymatic and electro-enzymatic activity of immobilized enzyme and provides accessibility towards substrate, various host materials (electropolymerized polypyrrole films, alginate polysaccharide, biocompatible synthetic latex and inorganic clays (laponite and layered double hydroxides LDHs), differing in permeability, ion exchange properties and hydrophobic–hydrophilic character, were compared for the fabrication of amperometric glucose biosensors. The electrochemical assays were performed by potentiostating the enzyme electrodes at 0.6 V vs. Ag/AgCl in order to oxidize the hydrogen peroxide enzymatically generated in the presence of glucose and oxygen. The highest sensitivity and maximum current density were recorded for laponite (82.3 mA M− 1 cm− 2 and 410 μA cm− 2 respectively) and LDHs (55 mA M− 1 cm− 2 and 417 μA cm− 2, respectively).