Development Of Immunoassays For Two Typical Emerging Organic Pollutants Detection And Application In Environmental Investigation

Tetrabromobisphenol A bis?2-hydroxyethyl?ether?TBBPA-DHEE?and dibutyl phthalate?DBP?are considered as two typical emerging organic pollutants.TBBPA-DHEE is a main derivative of tetrabromobisphenol A,which was widely used in the production of electronic circuit boards,adhesives and coatings.DBP is the most commonly used plasticizer in PVC products and applied in the processing and production of plastic products.These two substances can enter the environments after excessive useage,and then remain and accumulate in a multi-media environment and cause harm to human.Therefore,it is of great importance to establish efficient,sensitive and fast methods to analyze these two pollutants.The traditional immunoassays have the advantages of fast analysis and simple pretreatment,which could be used for the detection of TBBPA-DHEE and DBP in the environments.However,due to its insufficient sensitivity and weak tolerance against matrix interferents that potentially influce the performance of the method,it cannot meet the requirement of trace contaminents determination from complex samples.So this study introduced nano-enzymes into the coventional immunochemical techniques depending on their high catalytic activity and good resistance to matrix.Besides,the constructed improved immunoassays showed,stable and sensitive,which were applied for analysis the organic contaminents from various environmental samples,and detailed information are as follows:?1?A high-throughput,indirect competitive immunoassay was established based on the principle of CuMnO₂ nanosheet-type peroxidase for the analysis of environmental DBP.In the detection system,CuMnO₂ nanosheets were substituted for HRP in conventional ELISA,which was coupled with Ab₂ to form a signal probe?CuMnO₂@Ab₂?.Under the optimized conditions,the detection limit of this method can reach 2.07?g/L,implying four times lower than that using ELISA with the same antibodies.Meanwhile,good accuracy and precision?recoveries,78.49-138.5%;CV,3.16-7.55%?were obtained.Because the environemtnal samples have extremely low concentrations of target,this proposed method cannot directly measure environmental DBP because of its sensitivity?concentrations<2.07?g/L?.?2?In order to solve the shortcomings of insufficient sensitivity in the previous work,a dual-signal indirect competitive immunoassay was constructed using a double-functional nanomaterial H-MnO₂@C-dots for rapid analysis of DBP.At the present study,the signal amplification was achieved through the co-catalysis of C-dots and Mn?II?on TMB.Under optimal conditions,this method exhibits excellent performance:?1?high sensitivity?LOD,0.24?g/L?,and the LOD is 8 times lower than the ordinary ELISA;?2?good accuracy and repeatibility?recoveries,77.97-114.61%;CV,3.17-7.26%?.Using this method,large-scale investigation and research on the pollution status of DBP in the environment can be carried out to evaluate its environmental risks.?3?Based on the Co²⁺/hemin cooperative catalytic mechanism,a high-throughput,high-sensitivity indirect chemiluminescence immunoassay was constructed for the determination of TBBPA-DHEE in the environment,depending on Co²⁺/hemin synergistic catalysis to further amplify the signal.Under optimal conditions,the detection limit of this method is 0.9?g/L with good accuracy and stability?recoveries,89.67-125.33%;CV,2.75-8.37%?.Using the constructed method,30 water samples and 10 soil samples from Jiangsu and Zhejiang were analyzed.In all positive samples,the detected concentrations of TBBPA-DHEE in waters ranged from2.4-3.7?g/L;the concentration of pollutants in soils was 1.8-2.4 ng/g.