Microchimica Acta Analytical Sciences Based on Micro-and Nanomaterials

We report on the preparation of a nanoporous flat electrode by drop casting a nanocomposite consisting of re- duced graphene oxide (rGO) and chitosan onto a polyester substrate. An underlying conductive surface is not required. The nanocomposite was characterized by scanning electron mi- croscopy and electrochemical impedance spectroscopy. The 3D network of the composite was used as a scaffold for the immo- bilization of glucose oxidase (GOx). A well-defined signal re- lated to direct GOx electrochemistry was registered and used to monitor levels of glucose. The resulting biosensor displays a linear response to glucose with a detection limit of 5 μM (at an S/N ratio of 3) and a sensitivity of 41.7 μA⋅mM−1 cm−2. The sensor was applied to the determination of glucose in artificial saliva.