Research On Environmental Pollutant Detection Methods Based On Evanescent Wave Fluorescence Biosensor System

In recent years,pollution has attracted more and more attention.Traditional detection technologies are complex,time-consuming and expensive,which requires the development of rapid,high sensitive and low-cost new detection methods for pollutants in water.Online analyzer determination of 2,4-D was introduced in this paper,based on the multi-channel Triplex^TM waveguide fluorescence biosensor and the determination of BPA,2,4-D,MC-LR,based on the liposome Cy5.5 sensors as a signal amplification effect determination of 2,4-D three detection methods research.The three sensors are using the principle of evanescent wave fluorescence immunoassay biosensor,it can be fast,high sensitivity detection of pollutants,and realize the water pollutant,online,real-time detection of synchronization.Main findings:?1?The detection interval of 2,4-D of the online analyzer was7.1⁶0.1?g/L,and the detection interval was over 1 order of magnitude;The detection limit of 2,4-D is calculated to be 3.8?g/L.Online analyzer to 20 times 2,4-D antibody parallel determination,results show that the sensor chip signal response value of relative standard deviation is 4.4%?<20%?,shows that the stability of the sensor chip is higher,can be used repeatedly.In this experiment,the actual water samples were used to prepare the sample of different concentrations,and the test capability of the sensor system was studied.The results showed that the recovery rate was between 81%and 88%,and the variation coefficient was within 6%.It shows that the online analyzer has good accuracy and stability,and can be used for on-line real-time detection of 2,4-D in real water samples.?2?Based on this Triplex^TM waveguide multi-channel fluorescence biosensor,an indirect competitive immune detection model was used to optimize and establish standard test conditions for BPA,2,4-D and MC-LR of water environmental pollutants.After optimization,the antibody concentration of BPA was 1?g/mL,the antibody concentration of 2,4-D was 1?g/mL,and the antibody concentration of MC-LR was1?g/mL.The sampling time is 600s;The pre-reaction time is 600s.In the optimized conditions,the standard curve was measured:the IC50 values of 2,4-D,BPA and MC-LR to be 19.06?g/L,1.010?g/L and 2.979?g/L respectively.The detection range of BPA was 0.16⁶.43?g/L,and the detection range was over 2 orders of magnitude.The detection interval of 2,4-D was 2.8¹30.2?g/L,and the detection interval was over 2orders of magnitude.The detection interval of MC-LR is 0.56¹5.7?g/L,and the detection interval is over 3 orders of magnitude.The detection limit of BPA was0.05?g/L,the detection limit of 2,4-D was 0.9?g/L,and the detection limit of MC-LR was 0.18?g/L.Using 0.5%SDS?pH 1.9?as activating fluid,the sensor chip was regenerated.The signal response result of 20 times of continuous test,the standard deviation of the signal value is less than 20%,indicating that the chip has good regenerative stability and can be used repeatedly.In this experiment,the test capability of the sensor system for the actual water samples was studied by drinking bottled water,tap water and water preparation and standard samples of the lotus pond of Tsinghua university.The results showed that the recovery rate of the tap water was between 84%and 116%,and the variation coefficient was within 16%.The standard recovery rate of bottled water is between 95%and 120%,and the variation coefficient is within 8%.The index recovery rate of water in lotus pond is between 83%and 120%,and the variation coefficient is within 8%.The sensor has good accuracy and stability,and can be used for simultaneous detection of BPA,2,4-D and MC-LR in actual water samples.?3?By reverse evaporation method,Cy5.5 liposomes were prepared and characterized by DLS,atomic force microscope,scanning electron microscopy and other means.The liposomes are round or elliptic,with a particle size of 300.9A±20.7nm.The standard curve of Cy5.5 concentration and signal value was plotted with the intensity value and the fluorescence signal value as the horizontal ordinate.In collect after dealing with the micro column centrifugation of eluent on fiber optic instrument measuring the fluorescence signal value,the maximum minus the baseline is worth to the valid values into the standard curve,get the Cy5.5 concentration corresponding C0.Finally,the encapsulation rate was calculated to be 1.9%.The preparation of liposome biosensor is the preparation of antibodies,to combination of liposomes and antibodies,and the modification of optical fibers.Liposome biosensors were used to determine the2,4-D standard curves,but the results could not be used to synthesize the Rodgers curve.The reason may be that the liposome encapsulation rate was too low to cause a change in signal value.However,due to the limited time,although Cy5.5 liposomes were used as signal amplification to determine 2,4-D,the work did not achieve good results.Therefore,it is proposed to improve the encapsulation rate of Cy5.5 liposomes from various aspects such as the ratio of reagents,Cy5.5 concentration,rotation evaporation time,and size of liposomes.However,due to the limited time,although Cy5.5liposomes were used as signal amplification to determine 2,4-D,the work did not achieve good results.Therefore,it is proposed to improve the encapsulation rate of Cy5.5 liposomes from various aspects such as the ratio of reagents,Cy5.5 concentration,rotation evaporation time,and size of liposomes.This experiment established online analyzer determination of 2,4-D,based on the multi-channel Triplex^TM waveguide fluorescence biosensor and the determination of BPA,2,4-D,MC-LR,based on the liposome Cy5.5 sensors as a signal amplification effect determination of 2,4-D three research methods,can be used in actual water samples of BPA,2,4-D,MC-LR,online,real-time detection at the same time.They not only can realize synchronous,rapid and sensitive detection of pollutants in water,and chip regeneration stability is good,can be repeated use,for environment pollution accident treatment and early warning monitoring to provide technical support.