Research Of ECL Sensor For Three Environmental Pollutants Based On Nanocomposites And Aptamers

Environmental pollutants are easily enriched in the ecosystem,which can disturb the normal life activities of organisms and threaten human health.Therefore,it is of great significance for human health and environmental monitoring to develop and improve ultra-sensitive detection technology.In this paper,three kinds of nanocomposites used for the amplification of electrochemiluminescence signals were prepared by chemical oxidation method using the electrochemiluminescence（ECL）technology with high sensitivity,good selectivity and easy operation,and luminol with high quantum yield,low cost and no toxicity was used as the electrochemiluminescence reagent.Based on the conformational changes of the highly specific aptamers combined with the target,a novel ECL aptasensor was constructed to detect Hg²⁺,17β-estradiol（E2）and bisphenol A（BPA）.The main work includes the following four parts:1.In the introduction part,firstly,the two principles of electrochemiluminescence technology,the principle and application of electrochemiluminescence aptamer sensor are introduced;secondly,several environmental pollutant aptasensor such as colorimetric sensor,fluorescence sensor and electrochemistry sensor are introduced.The electrochemilumin-escence aptasensor for environmental pollutants are mainly introduced,and the applications of several nanomaterials（metal nanoparticles,carbon nanomaterials,quantum dots,etc.）in electrochemiluminescence aptasensor are reviewed at last.2.In this work,a label free and highly sensitive Electrochemiluminescence aptasensor was developed for the sensitive and selective detection of Hg²⁺without additional coreactants.Poly（aniline-luminol）/graphene oxide（P（ANi-Lu）/GO）nanocomposites were prepared,and chitosan（CS）was used to modify the surface of the material,which made the surface of the material was positively charged.The P（ANi-Lu）/GO/CS exhibited a stable and excellent electrochemiluminescence properties.Aptamer was adsorbed on P（ANi-Lu）/GO/CS sensing interface,and Hg²⁺was detected using T-Hg²⁺-T configuration as ECL intensity controller.The results showed that Hg²⁺can be quantitatively determined in the range of 1.0×10^-15～1.0×10^-7 M with a detection limit of 4.8×10^-16 M.3.In this chapter,poly（aniline-luminol）/silver（P（ANi-Lu）/Ag NPs）nanocomposites were prepared by chemical oxidation method.The synthesis method is simple,and the P（ANi-Lu）/Ag NPs nanocomposites can have excellent ECL performance without adding additional co-reactants.Based on E2 aminated aptamer modified P（ANi-Lu）/Ag NPs.Under the optimal experimental conditions,the ECL sensor has a wide linear range(1.0×10^-14～1.0×10^-5 M)and a low detection limit(8.0×10^-15 M)for E2 detection.In addition,when detecting E2 in tap water and industrial wastewater,a good recovery rate was obtained.4.In this chapter,an ECL aptasensor based on chitosan/luminol/gold/graphene oxide（CS/lu/Au NPs/GO）nanocomposites synthesized by chemical oxidation method is proposed.By using the electrocatalytic ability of gold nanoparticles,the ECL signal response of the system can be significantly amplified without adding co-reactants.The construction process of ECL aptasensor is relatively simple,which can realize the ultra-trace analysis of bisphenol A.Under the optimal experimental conditions,there is a good linear relationship between the difference of electrochemiluminescence intensity before and after the aptamer incubation with bisphenol A and the logarithm of bisphenol A concentration.The linear range is 1.0×10^-15～1.0×10^-6M,and the detection limit is 7.6×10^-16M.At the same time,the sensor can be used as a new ECL platform to accurately detect BPA in actual water samples.