Research On Application Of Luminescence And Immunoassay For Persistent Organic Pollutants

With the rapid development of modern industrial technology, more and morechemicals released to the natural environment cause serious harm to both theenvironment and human health, and the vigilance of people for these chemicals is alsorising. A class of substances known as persistent organic pollutants（POPs） which arestable, bioaccumulative, toxic and persistent have become a hot issue of globalconcern. And those pollutants, which also possess immunotoxicity, endocrine toxicity,as well as other toxic effects and probably pose reproductive and developmentalfailure, bring an increasing number of health and environmental problems.At present, Most of these methods are based on gas/liquidchromatography（GC/LC）, high-performance liquid chromatography（HPLC）-tandemmass spectrometry（MS）, as well as GC-MS. Although the good sensitivity has beenachieved, these instrumental methods require expensive instrumentation, extensivesample pretreatment（purification, concentration and/or derivatization）, large amountsof organic solvents, other chemicals as well as often complicated cleanup.Sodevelopment quick screening and biological analysis method of POPs is of greatsignificance.Fluorescence and electrochemiluminescence（ECL） method are all good methodsfor detection which have high sensitivity, and regarded as the methods which havelarger potential on detection. The highlighted merits of fluorescence are highsensitivity and high selectivity, simple and direct, light sample, and simple instrument,so fluorescence is regarded as one of the most sensitive detecting methods.Fluorescence has been widely used in the field of environmental monitoring and lifescience. Immunoassay which is sensitive, specific, fast, as well as low-cost, can beapplied to routine analysis of a large of samples, and be also used for qualitativescreening and quantitative determination of samples. Immunoassay methods havebeen widely used in the field of clinical diagnostics, environmental monitoring,pharmaceutical research food quality, and agriculture. ECL has the several features ofchemiluminescence and electrochemistry which have high sensitivity, wide linearityrange, simple instrument, fast analysis, easy control and easy detection of theluminescent signal.Based on above, we developed three works as below in this article: （1） Indirect Fluorescence for the determination of pentachlorophenol:pentachlorophenol（PCP） doesn’t have the property of fluorescence, and it is a greatchallenge to establish fluorescence analysis of pentachlorophenol. Ce³⁺can emitstrong fluorescence; Ce⁴⁺is no fluorescence, and PCP can consume the hydroxylradical; it have been found experimentally that hydroxyl radicals generating fromH2O₂catalyzed by horseradish peroxidase（HRP） oxidized Ce³⁺to Ce⁴⁺, causing thefluorescence quenching of Ce³⁺; the addition of PCP has an inhibitory effect on thereaction. Based on this observation, a novel method by indirect fluorescence to detectPCP has been proposed. This method doesn’t have complex fluorescent markerreaction. The linear range is from1.0×10-8to1.0×10-4M, and the detection limit is5.0×10-9M.（2） Fluorescence Polarization Immunoassay for the Determination ofOctachlorostyrene: The anti-OCS antibody is derived from immunization of rabbitsfor the first time. Rhodamine B labeled-hapten served as a fluorescent-labeled haptenshowed a good binding to anti–OCS antibody. The analytical fluorescently labeledsmall antigen when bound by a specific antibody was developed. Under the optimizedconditions, this FPIA shows a linear detection range from0.65to650nM and adetection limit of0.34nM. Recovery rates are higher than90%. This assay is moresimple and quick than other analytical methods, such as high performance liquidchromatography and gas chromatography. Thus, the proposed FPIA method could be auseful tool for filed test in environmental, biological, and agricultural samples.（3） Homogenous electrogenerated chemiluminescence immunoassay of tris （2,3–dibromopropyl） isocyanurate: luminol-hapten served as the luminescence andanodized TiO₂nanotubes as the working electrode. Anti–tris （2,3–dibromopropyl）isocyanurate（TBC） antibody is derived from immune New zealand male rabbitpreparation. The luminol–hapten shows high ECL intensity. While the luminol–haptenforms immunocomplex with the anti–TBC antibody, the ECL is quenched. When TBCis introduced, the specific immunoreaction between TBC and antibody formsimmunocomplex releasing the luminol–labled TBC, leading to the recovery of theECL intensity. The TBC–resulted increase in ECL intensity is linear dependent on thelogarithm of TBC concentration in the range from0.42to170nM with a detectionlimit of0.2nM and relative standard derivation of <5.5%. High sensitivity andselectivity were obtained. The practicability of the proposed ECL method wasevaluated by the analysis of TBC content in the outlet of a TBC manufacturing plantalong Liuyang River, and the TBC contents is0.53nM, which shows that the proposed method can be applied as an in-site fast scaning method for TBC.