Characterization and Applications of Modified Gold Electrode Sensor with Nanoparticles
S.W. Leung, Y. Wang, H. Gu, J.C.K. Lai
Idaho State University, US
Keywords: biosensor, nanoparticle, hemoglobin, nitrite, nitrate, electrode
Abstract:In the recent development of biosensor, response time of the sensor is drastically improved by using direct coupling of enzymes onto the surface of electrode. The drawback of the direct coupling of enzymes is denature of enzymes on the surface of electrode during the cycles of redox reactions. In order to develop sensors that are useful with predictable performance, the sensors must be well characterized under working conditions so that the performance is ensured. We are developing a biosensor with gold electrode modified by surface coating of cysteamine coupled with nanoparticles then with hemoglobin (Hb). Due to the high chemical affinity of hemoglobin with nitrite, this Au-cysteamine-nanoparticle-Hb biosensor can be used to detect nitrite/nitrate by means of a cyclic voltammographic technique. The detection limit of nitrite/nitrate of this biosensor was well below mM and its response time was almost instantaneous. The reproducibility of performance was tested, and the chemical kinetics of the nitrite/nitrate redox reaction on the surface of the modified electrode was studied. This sensor was further characterized by the oxidation of peroxide and the results will be reported.