Carbon Nanotubes Based Glucose Needle-type Biosensor

A novel needle-type biosensor based on carbon nanotubes is reported. The biosensor was prepared by packing a mixture of multi-wall carbon nanotubes (MWCNTs), graphite powder and glucose oxidase (G(ox)) freeze-dried powder into a glass capillary of 0.5 mm inner diameter. The resulting amperometric biosensor was characterized electrochemically using amperometry in the presence of hydrogen peroxide and in the presence of glucose. The glucose biosensor sensitivity was influenced by the glucose oxidase concentration within the MWCNTs mixture. The optimized glucose needle-type biosensor displayed better sensitivity and stability, and a detected range of up to 20 mM. Based on its favorable stability, the needle biosensor was first time used in real-time monitoring system as a kind of online glucose detector. The decay of current response is less than 10% after 24-hour continuous observation.