Fabrication of SnO2-ZnO nanocomposite sensor for selective sensing of trimethylamine and the freshness of fishes

SnO2 nanoparticles and ZnO microrods were prepared and characterized by X-ray diffraction (XRD) and a field emission scanning electron microscope (FESEM). The results showed that the mean grain size of the SnO2 nanoparticles was 40 nm; the diameter of ZnO microrods was about 1-1.5 mu m with a length between 8 and 10 mu m. The gas-sensing properties of the SnO2 nanoparticles, ZnO microrods and the nanocomposite of SnO2 nanoparticles doped with 5-15 wt% ZnO microrods were investigated. The gas-sensing properties of the SnO2 nanoparticles were greatly improved by doping with the ZnO microrods. The SnO2-ZnO nanocomposite sensor showed high and quick response to trimethylamine (TMA) at 190-330 degrees C. This sensor showed the advantages of high selectivity, excellent sensitivity, strong stability and prompt response/recovery characteristics in detecting TMA at 330 degrees C. It could be used to detect the freshness of fishes. (C) 2008 Elsevier B.V. All rights reserved.