A new osmium-polymer modified screen-printed graphene electrode for fructose determination

This paper describes the development and performance of the first fructose biosensor based on a com-mercial screen-printed graphene electrode (SPGE). The electrode was modified with an osmium-polymer,which allowed the efficient wiring of the enzyme fructose dehydrogenase (FDH). The immobilization ofboth osmium-polymer and FDH was realized in an easy way. Aliquots of 10 microL Os-polymer and 10 microLFDH were thoroughly mixed with poly(ethylene glycol) (400) diglycidyl ether (PEDGE) and deposited onthe electrode surface and left there to dry overnight. The biosensor exhibits a detection limit of 0.8 microM, a linear range between 0.1 and 8 mM, high sensitivity to fructose (2.15 microA cm−2/mM), good reproducibility( RSD = 1.9%), fast response time (3 s) and a stability of 2 months when stored in the freezer.The proposed fructose biosensor was tested in real food samples and validated with a commercial spectrophotometric enzymatic kit. No significant interference was observed with the proposed biosensor.