Study On Environmental Bioanalytical Methods For Two Novel Organic Pollutants

Emerging organic pollutants are artificially synthesized or natural substances,which could cause potential ecological and health risk when be discharged into environments,including antibiotics,personal care products,surfactants,artificial sweeteners,pesticides and various industrial additives.These chemicals exist in real environments but lack extensive ecotoxicological data.So it is necessary to develop reliable,simple and sensitive methods for detect them.Currently available methods for determination of DBP in environmental samples are mainly based on the chromatographic methods,although the methods have good accuracy and high sensitivity.However,the approaches have time-consuming sample pretreatment and high cost,these drawbacks limited their application to some extent.In this paper,sensitive and reliable immunoassays were established for determination of two merging organic pollutants(dibutyl phthalate,DBP;tetrabromobisphenol A dihydroxyethyl ether,TBBPA-DHEE),and the methods were successfully applied for analysis of samples from real environments.The details are shown as following:(1)For DBP,we developed an electrochemical impedimetric immunosensor.The approach was based on an indirectly competitive binding system of coating antigen that coated on antigen/chitosan/MWCNTs@GONRs/GCE(modified electrodes),target(DBP)and anti-DBP antibody.Signal amplification was performed via the enlargement of AuNPs through NADH-promoted catalytic precipitation,which caused a marked increase in the electron-transfer resistance and electrostatic repulsion after an AuNP-labeled second antibody conjugated to anti-DBP.Under the optimized conditions,this method displayed:(i)low detection limits(7 ng m L-1,10 times lower than the traditional ELISA method using the same antibody);(ii)high tolerance to some environmental interferents;and(iii)low cost and low sample consumption(6 ?L).Our results demonstrate the great potential and high efficiency of this immunosensor in practical applications for the cost-effective and sensitive monitoring of DBP in aquatic environments.(2)For TBBPA-DHEE,there has been little data reported on its chemicals due to the lack of widely available analytical methods.Therefore,it is necessary to establish a simple,sensitive and reliable analytical method to investigate its pollution characteristics in the environment and then assess its ecological risk.In this study,the synthesis of a hapten and the production of a polyclonal antibody to simultaneously recognize TBBPA DHEE and TBBPA MHEE was described.Accordingly,a sensitive indirect competitive enzyme-linked immunosorbent assay(ic-ELISA)was established for determination of TBBPA DHEE and TBBPA MHEE.In optimized conditions,the respective detection limit(LOD,based on 90% B/B0)and IC50 calculated from the standard curve were 0.7018 and 9.868 ng mL-1.The analytical method showed acceptable accuracy(recoveries of 83-133%)and good tolerance to matrix interferents,which indicates that the approach holds great potential for detecting environmental organic pollutants.This was the first time we found the presence of TBBPA DHEE in environmental water samples.(3)For TBBPA-DHEE,a high sensitivity chemiluminescence immunoassay(CLEIA)method was established by using the above polyclonal antibody.The detection limit was 0.801 ng mL-1 and the IC50 value was 8.9985 ng mL-1.This method was used to analyze the pollutants in environmental water.And compared with the established ELISA.Which provided reference data for the subsequent study of CLEIA of TBBPA-DHEE.