Nanomolar Detection of Glutamate at a Biosensor Based on Screen-Printed Electrodes Modified with Carbon Nanotubes

The flow injection analysis (FIA) of monosodium L-glutamate (MSG) was performed electrochemically using a biosensor based on screen-printed electrodes containing carbon nanotubes (CNT). The sensor was fabricated by simply adsorbing glutamate oxidase (GlutOx) on the electrode surface. The resulting device displayed excellent electroanalytical properties toward the determination of L-glutamate in a wide linear range (0.01-10 mu M) with low detection limit (10 nM, S/N >= 3), fast response time (<= 5 s), and good operational and long-term stability. The CNT-modified screen-printed electrodes have a potential to be of general interest for easy preparation of electrochemical sensors and biosensors relevant for biomedical applications.