Study On The Construction And Performance Of Electrochemical Sensors For Several Benzene Ring Organic Pollutants

With the advance of China's industrialization,people's demand for chemicals is increasing.Meanwhile,a variety of toxic and harmful organic pollutants have been brought into the environment,and make the world environmental pollution problems become serious increasingly.Among them,benzene ring organic pollutants with closed conjugated delocalized large?bonds with sp² hybrid orbital bond have aroused people's attentions,because of their high toxicity,bioaccumulation,strong stability,difficultly to metabolize in the environment and the human body and other reasons.To achieve its quantitative analysis is imminent.Electrochemical sensors are widely used in biotechnology,food industry,clinical detection,environmental monitoring and other fields due to its simple-pretreatment,low-cost,easy operation,fast reaction and can be used for on-site inspection.Based on the problems in the electrochemical detection of benzene-based organic pollutants,three kinds of nano-materials modified electrodes were constructed in this paper.And the organic pollutants of benzene ring were quantitatively analyzed.The details were as follows:1)Preparation of bisphenol A electrochemical sensors based on molecular imprintingThe electroreducted graphene oxide?ERGO?,polymelamine?PMel?,gold nanoparti-cles?AuNPs?and molecular imprinted films?MIP?modified on the surface of the glassy carbon electrode were carried out by electrochemical deposition and electrochemical polymerization to prepare the molecular imprinted electrochemical sensors.Under the optimal experimental conditions,the MIP/AuNPs/PMel/ERGO/GCE sensor had a good linear relationship with BPA in the range of 50³00?M.The detection limit was 9.9?M?S/N=3?.2)Electrocatalytic properties of 3D graphene-supported PdCu nanocapsules for aromatic nitro compoundsThe electrochemical sensors of aromatic nitro compounds?NACs?were successfully constructed by modifying the 3D graphene-supported PdCu nanocapsules?Pd-Cu/3DGSs?onto the surface of glassy carbon electrode by dropping method.At the same time,a detailed electrochemical study of p-nitrophenol?p-NP?was carried out by the sensor.The results showed that the Pd-Cu/3DGSs have good electrocatalytic activity for NACs.Under the optimum experimental conditions,the current response of the sensor to p-NP showed a good linear relationship with the concentration of p-NP in the range of 10³000?M.The detection limit was 0.050?M?S/N=3?.3)p-Nitrophenol electrochemical sensors based on AgNPs/PB compositesCyclic voltammetry was used to prepare the iron complex,prussian blue?PB?,modified on the surface of the glassy carbon electrode.And the silver nanoparticles?AgNPs?were electrodeposited for quantitative analysis of p-NP.The results showed that the prepared sensor had good catalytic ability for the electrochemical reduction of p-NP.The reduction potential of p-NP was shifted from-0.73 V to-0.43 V from the bare electrode.At the same time under the optimized conditions,in the range of 100⁵00?M and 500³000?M,the concentration of p-NP was linear with its reduction peak current.The detection limits were 0.32?M?S/N=3?.To sum up,three types of electrochemical sensors were prepared by modifying the glassy carbon electrode with nanomaterials.They were characterized electrochemically and used to detect BPA,NACs and p-NP,respectively.The constructed sensors with the advantages of simple operation,fast response,good stability and reproducibility provide a kind of new method for the electrochemical detection of benzene ring organic pollutants.