Nanobiocomposite Electrochemical Biosensor Utilizing Synergic Action of Neutral Red Functionalized Carbon Nanotubes

摘要

An amperometric hydrogen peroxide biosensor using a nanobiocomposite based on neutral red modified carbon nanotubes and co-immobilized glucose oxidase and horseradish peroxidase is reported. Modification of the nanobiocomposite electrode with neutral red resulted in a sensitive, low-cost and reliable H2O2 sensor. The use of carbon nanotubes, as the conductive part of the composite, facilitated fast electron transfer rates. The biosensor was characterized for the influence of p H, potential and temperature. A remarkable feature of the biosensor is the detection of H2O2 at low applied potentials where the noise level and interferences are minimal. The sensor has a fast steady-state measuring time of 10 s with a quick response（2 s）. The biosensor showed a linear range from 15 n M to 45 m M of H2O2 and a detection limit of 5 n M. Nafion, which is used as a binder, makes the determination free from other electroactive substances. The repeatability, reproducibility,stability and analytical performance of the sensor are very good.