A novel amperometric glucose sensor based on PtIr nanoparticles uniformly dispersed on carbon nanotubes

A novel amperometric nonenzymatic glucose sensor based on PtIr nanoparticles deposited on carbon nanotubes (PtIr/CNT hybrids) has been successfully fabricated and applied to the nonenzymatic glucose detection. Their electrochemical behavior toward the oxidation of glucose was compared with Pt nanoparticles deposited on carbon nanotubes (Pt/CNT hybrids) prepared with a similar procedure. In PtIr/CNT hybrids, PtIr nanoparticles were homogeneously dispersed on carbon nanotubes with an average diameter of 2.0 nm. Their size can be controlled by tuning the Pt/Ir ratio. In contrast, Pt nanoparticles are unevenly distributed on carbon nanotubes with an average diameter of 5.0 nm. The PtIr/CNT hybrids modified electrode shows a highly electroactive surface area, and displays a greatly enhanced electrocatalytic activity toward glucose oxidation. Chronoamperometry was applied to glucose detection in 0.2 M phosphate buffer solution (pH 7.4). The effect of the size of PtIr nanoparticles and the applied potential was investigated. The as-prepared PtIr/CNT hybrid based glucose sensor significantly shows a higher sensitivity, a lower detection limit and a wider linear range than those of Pt/CNT modified electrode. Moreover, Ir addition in Pt catalysts can enable the amperometric glucose detection with longer stability even in the presence of the interference such as ascorbic acid, uric acid, 4-acetamidophenol, creatinine and cholesterol. These results indicate that the PtIr/CNT hybrids are a promising candidate for a highly sensitive and selective nonenzymatic glucose sensor.

► PtIr nanoparticles were uniformly deposited onto carbon nanotubes.
► The size of PtIr nanoparticles can be controlled by tuning the composition.
► These hybrids can be used as a nonenzyme sensor in glucose detection.
► This sensor shows a great enhancement in sensitivity, selectivity and stability.