Water-Soluble Reduced Graphene Oxide-Carboxymethylcellulose Hybrid Nanomaterial for Electrochemical Biosensor Design

A novel hybrid nanomaterial was synthesised by covalent attachment of O‐carboxymethylcellulose to reduced graphene oxide. Graphene oxide was first anchored with (3‐aminopropyl)triethoxysilane moieties to provide reactive primary amino groups at the basal plane. Periodate‐oxidised O‐carboxymethylcellulose was further covalently attached to this aminated nanomaterial through reductive alkylation with NaBH4. Stable aqueous dispersions were obtained with the resulting hybrid nanomaterial, which was used to coat glassy carbon electrodes. Furthermore, the enzyme tyrosinase was covalently immobilised and the nanostructured enzyme electrode was successfully employed for the amperometric detection of catechol in the 20 nM–56 μM range. The biosensor showed excellent analytical performance with a high sensitivity of 270 mA M−1 and a low detection limit of 0.2 nM. Construction site: A novel water‐soluble graphene derivative prepared by covalent grafting with carboxymethylcellulose and its use as a nanostructured scaffold for tyrosinase biosensor construction is described (see figure).