| With the rapid development of science and technology and industrial economy, some typical toxic and harmful organic pollutants have been brought into the environment inevitably, with obtaining large quantities of chemicals to meet the needs of economy, production and life. Some of the organic pollutants have been proved to be carcinogenic,-teratogenic and mutagenic, which cause multiple damage and potential threat to the natural ecological environment and human health.For the electrochemical detection of environmental pollutants, in this paper a series of nano composite modified electrodes were constructed and used for the determination of trace organic pollutants in the environment. The main researeh work is deseribed as follows:1) Construction and application of naphthol based electrochemical sensorsA glassy carbon electrode (GCE) modified by graphene oxide (GO) and L-Cysteine (L-Cys) composite film was prepared successfully by the method of dispensing and electro-polymerization. The results showed that the difference of oxidation peak potential between 1-naphthol and 2-naphthol could reach 182 mV, which was large enough to achieve the simultaneous detection for 1-naphthol and 2-naphthol in mixed solution. Differential pulse voltammetry was adopted to detect naphthol isomer, under the optimized experimental conditions. Two oxidation peak currents showed good linear relationship with the concentration of 1-NAP and 2-NAP in the range form 2 ?mol/L?40 ?mol/L and 1 ?mol/L?40 ?mol/L, respectively. The detection limits (S/N=3) for 1-NAP and 2-NAP were 0.19 ?mol/L and 0.12 ?mol/L, respectively. The modified electrode showed good stability and reproducibility and had strong anti-interference ability in the detection.2) A novel sensor for detection of bisphenol A based on graphene and gold and ruthenium (ERGO-Au2Ru1) and ?-cyclodextrin (?-CD) composite modified glassy carbon electrodeA glassy carbon electrode (GCE) modified by the nanocomposites of graphene and gold and ruthenium (ERGO-Au2Ru1) was prepared successfully by the method of one-step electrodeposition. Considering that ?-cyclodextrin can recognize bisphenol A, P-CD/ ERGO-Au2Ru1 modified GCE was completed by electro-polymerization. Under the optimum conditions, the linear relationship between the oxidation peak current and the concentration of bisphenol A can be obtained in the range from 0.05 ?mol/L to 40 ?mol/L with the detection limit as 5.3 nmol/L (S/N=3). The sensor showed good stability, reproducibility and anti-interference, and provided an alternative method for detection of bisphenol A. Besides, the electrochemical sensor has the potential to be applied to the determination of bisphenol A in environmental wastewater.3) Electrochemical sensor for nitrobenzene detection based on silver nanoparticles supported on poly(melamine) functional multi-walled carbon nanotubesA high sensitive electrochemical sensor based on silver nanoparticles supported on poly(melamine) functional multi-walled carbon nanotubes (AgNPs/PMel/MWCNTs) modified glassy carbon electrode (GCE) was fabricated for the quantitative detection of nitrobenzene (NB). The analysis results showed that the sensor had strong electrocatalytic activity for the electrochemical reduction of NB. The reduction peak potential of NB was moved from -0.68 V to -0.44 V on the modified electrode. The peak current achieved under the optimum conditions was linear with the NB concentration ranging from 20 to 1000 ?mol/L and from 1000 to 6000 ?mol/L respectively, with the detection limit 0.55 ?mol/L (S/N=3). |
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