The Study On Environmental Contaminant Detection Based On Planar Waveguide Florescence Immunosensor

Based on the principles of Total Internal Reflection Fluorescence theory and immunoassay, the Multiple Planar Waveguide Florescence Immunosensor(MPWFI) was developed in the research. The sensor system can detect trace pollutants in aquatic environment quickly and quantificationally. In this study, an innovative automated online optical biosensing system was developed by an indirect competitive detection mode, for the rapid detection and early warning of bisphenol A and sulfadimidine with single objective material detection and multiple objective material detection.This can provides a quick, simple and effective detection technical support for water environmental protection and food safety testing.Based on Multiple Planar Waveguide Florescence Immunosensor and its detection principle, the paper researches in four aspects: the optimization of bisphenol A detection conditions, the optimization of sulfadimidine detection conditions, the determination of bisphenol A under multi-channel, the matrix effect shielding measures. The main research results are as follows:(1) The optimal testing conditions are: the BPA antibody concentration is 0.05μg/m L, the sampling time is 300 s, the reaction time is 3 mins.Under optimized test conditions, typical calibration curves obtained for BPA has detection limits of 0.04 μg·L-1. Linear response ranged from 0.16 μg/L to 17.84 μg/L. The 50% inhibition concentration(IC50) were(1.67±0.47) μg·L-1.(2) Under the optimal testing conditions, typical calibration curves obtained for sulfadimidine has detection limits of 0.06 μg·L-1. Linear response ranged from 0.16 μg/L to 8.91 μg/L. The 50% inhibition concentration(IC50) were 1.20 μg·L-1(3) The interference experiment of bisphenol A and sulfadimidine showe that the antibody made by our group has good specificity.(4) Under the condition of multi-channel, the sensor system still has a high sensitivity.(5) By means of adding 0.5% EDTA and 1% BSA to sample solutions can weaken the interference of water hardness.(6) Under optimal conditions, the recovery rate of actual samples is between 88% to 111% and between 88% to 105% with RSD less than 10%. This method can be applied to practical detection of bisphenol A in water samples.The proposed method based on MPWFI biosensor is expected to have wide potential applications for onsite and rapid detection of various low molecular weight contaminants in environmental monitoring such as bisphenol A and sulfadimidine. It provided a simple and effective detection technology for rapid and sudden water pollution environmental emergency monitoring and food safety monitoring.