Influence of different nanozeolite particles on the sensitivity of a glucose biosensor

Four types of nanozeolite (NZ) particles (Silicalite S-1, BEA, Silicalite S-1-DT, and BEA-DT) with different physicochemical properties have been used for preparation of the new glucose oxidase (GOD) biosensor. Cyclic voltammetric studies were carried out with four different Pt/NZ electrodes, and it was found that the electrode prepared with BEA-DT NZ showed the highest electroactivity. These cyclic voltammograms (CVs) were compared with the CVs of four Pt/NZ-GOD electrodes. The presence of the oxidoreductase (GOD) on the electrode surface was the reason for the shifting of the potential peaks and corresponding currents. The magnitudes of the cathodic peak of Pt/NZ-S-1-GOD and Pt/NZ-S-1-DT-GOD electrodes had the highest values. The surface concentration (I*) of the adsorbed electroactive species (NZ-GOD) on the electrode was estimated according to the Brown-Anson model. The pH effect on the cathodic peak potential of Pt/NZ-GOD electrodes was investigated. The influence of different nanozeolites on sensitivity of GOD biosensors was studied. The most sensitive biosensor was obtained with NZ-S-1-DT, which had a porous surface, a higher degree of hydrophobicity, and a relatively high negative charge. The sensitivity of this electrode was 1.8044 μA L mmol(-1), the concentration limit was 0.8 mmol L(-1) glucose, and the linear correlation was from 2 to 18 mmol L(-1) glucose.