The Immobilization of Fructose Dehydrogenase on Nanoporous Gold Electrodes for the Detection of Fructose

Nanoporous gold electrodes were utilized as a support for the detection of d‐fructose. The immobilization of fructose dehydrogenase was achieved by adsorption on thiol‐ and diazonium‐bound carboxylic acid functional groups and subsequent crosslinking through cabodiimide‐initiated amide bond formation. The biosensor showed a linear response in the range 0.05–0.3 mM of d‐fructose with a sensitivity of 3.7±0.2 μA cm−2 mM−1 and a limit of detection of 1.2 μM. The response of the biosensor in a range of natural sweeteners and beverages compared very favorably to the results obtained by a commercially available kit. Accurate readings were obtainable after a very fast response time of less than 5 seconds. The biosensor showed high specificity towards d‐fructose in the presence of interfering sugars.