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

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

Analytical and bioanalytical chemistry (2012-10-24)
Paula Díez, Ciprian-George Piuleac, Paloma Martínez-Ruiz, Santiago Romano, María Gamella, Reynaldo Villalonga, José M Pingarrón
ABSTRACT

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 H2O2 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.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Cysteamine hydrochloride, ≥98% (titration)
Sigma-Aldrich
Cysteamine, ~95%
Sigma-Aldrich
Cysteamine, ≥98.0% (RT)
Sigma-Aldrich
Cysteamine hydrochloride, BioXtra
Sigma-Aldrich
Cysteamine hydrochloride, ≥97.0% (RT)