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 mu Acm(-2)mM(-1) and a limit of detection of 1.2 mu M. 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 5seconds. The biosensor showed high specificity towards d-fructose in the presence of interfering sugars.