Supramolecular immobilization of glucose oxidase on gold coated with cyclodextrin-modified cysteamine core PAMAM G-4 dendron/Pt nanoparticles for mediatorless biosensor design

Cysteamine core polyamidoamine G-4 dendron branched with β-cyclodextrins was chemisorbed on the surface of Au electrodes and further coated with Pt nanoparticles. Adamantane-modified glucose oxidase was subsequently immobilized on the nanostructured electrode surface by supramolecular association. This enzyme electrode was used to construct a reagentless amperometric biosensor for glucose, making use of the electrochemical oxidation of H 2 O 2 generated in the enzyme reaction. The amperometric response of the biosensor was rapid (6 s) and a linear function of glucose concentration between 5 and 705 μmol L −1 . The biosensor had a low detection limit of 2.0 μmol L −1 , sensitivity of 197 mA mol −1 L cm −2 , and retained 94 % of its initial response after storage for nine days at 4 °C.