Research On Methods For Detection And Degradation Of Organic Pollutants

Withtherapid development ofmodernagriculturaland industrial, theproblemofenvironmentalpollution is growing serious. Octachlorostyrene (OCS) is categorized as the most hazardous amongthe PBTs. So it is desirable to develop rapid and sensitive methods for the determination ofOCS.Atthe same time, degradation of persistent organic pollutants attracts great interests from governmentand many researchers. So this article has done some tentative work to fabricate high photocatalyticactivity ZnO film which be potential material of POPs degradation. And two novel and sensitivemethodhavebeendoneondeterminationofOCS.Theprimarycontentsareasfollows:1) A wireless, remote query octachlorostyrene (OCS) biosensor was fabricated by coating amass-sensitive magnetoelastic ribbon with anti-OCS antibody. In response to atime-varying magnetic field, the magnetoelastic sensor mechanically vibrates at acharacteristicresonancefrequencywhichinverselydependsonthesensormassloading.Asthe magnetoelastic film is magnetostrictive itself, the vibrations launch magnetic fluxthatcanberemotelydetected using apickup coil. Au nanoparticles(NPs) wereusedto amplifythe mass loading. In a sample solution containing OCS target and OCS-modified AuNPs(OCS-AuNPs), both OCS and OCS-Au NPs react with the anti-OCS antibodyimmobilized on the sensor surface in a competition mode. The bound OCS-AuNPsamount is inversely proportional to the OCS target concentration. The reduction of boundOCS-AuNPs induced by free OCS results in significant change in mass loading, whichamplifies the responses. The biosensor demonstrates a linear shift in resonance frequencywithOCSconcentrationbetween7.4μMto9nM,withadetectionlimit of1.6nM.2) Anovelhomogeneouselectrogenerated chemiluminescence immunoassay(ECLIA) forthedeterminationofsmallhaptens isdeveloped. Asamodelsystem,Octachlorostyrene(OCS)is investigated while luminol served as luminescence label and TiO2nanotubes acted as aworking electrode for ECL signal amplification. TBC derivative is directly labeled withluminol to form luminol–OCS. The ECL intensity of the immunocomplex markedlydecreased whenthe immunoreactionbetweenLuminol–OCS and anti–OCS antibodytookplace. A competitive immunoassay was proposed to determine OCS. The logarithm ofOCS concentration was linear within the range from6nM to0.384μM with a detectionlimit of2nM.3) Hereit isdemonstratedthat theAu-Ag-ZnO architecturecan be immobilized on indiumtin oxide (ITO) substratethrough afacile three-step synthesis approach. Aseries ofZnO filmswith different modifications of Au and Ag were applied to study the effect of Ag and Aunanoparticles on the morphology, optical properties and photocatalytic activity. Anannealing treatment of the ZnO nanosheets before Ag-Au deposition is found to play animportant roleinthepropertiesoftheAu-Ag-depositedZnOnanosheet (Au-Ag-ZnO).Theannealing treatment results in a significant increase in the surface area of ZnO, andconsequently an increase in the depositing amount of Ag nanoparticles. The Au-Ag-ZnOfilm shows nearly twice the photocatalytic efficiency than pure ZnO, and much higherefficiency comparing with the Ag-ZnO film in the photocatalytic degradation of methylorange(MO)underUVilluminationinaqueoussolutions.