Based On The Synthesis Of Nanocomposites And Electrochemical Sensor Used For Determination Of Environmental Pollutants

Electrochemical analysis has great advantages for its simple operation and high sensitivity, which contains electrochemical enzyme sensing technology and electrochemiluminescence sensing technology. With the development of nanotechnology, nanomaterials are widely used to the detection analysis in electrochemical analysis, and to make better, the nanotechnology and electrochemical analysis technology can detect the environmental pollutants. Under the background of the previous researchers, layered nanocomposites and fluorescent quantum dots are in preparation. The layered nanocomposites are used to electrochemical enzyme sensor, and the fluorescent quantum dots are applied to ECL sensor. based on the technology of electrochemical analysis, the environmental pollutants are detected. In this paper, This paper mainly is the composite of nanomaterials, and the application of electrochemical sensors, and the detection of pollutants, The main contents include the following aspects:1. Based on enzyme sensors of Au-HTiNbO5layered nanomaterials and for ultra-trace methyl parathion detectionAn ultrasensitive enzyme biosensor was developed for rapid detection of ultra-trace organophosphate pesticides (OPs). Loaded gold nanoparticles on the HTiNbOs nanosheets by photo-reduction method, and then Au-HTiNbO5nanocomposites were successfully synthesized. They were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM). Finally, the Au-HTiNbO5nanocomposites were employed to construct the biosensor for the detection of methyl parathion (MP). The whole process was characterized by cyclic voltammogram (CV) and electrochemical impedance spectroscopy (EIS). Experimental parameters such as the scan rate, the ATCl concentration and the pH value of electrolyte solution were studied to investigate the effect on the current density. Under the optimized conditions, the current density decreased linearly the MP concentrations in the range from5.0×10-12to5×10-9M, with detection limit of1.68×10-12M (S/N=3). The developed sensor exhibited wide detection range, low detection limit, good reproducibility and acceptable stability. Build the enzyme sensor of the Au-HTiNbO5nanocomposites can offer a new perspective for the detection of the environmental pollutants.2. Based on synthesis of the novel QDs and as ECL sensors materials for ultra-trace TNT detectionUnder N2atmosphere, The CdSe QDs were synthesized in water solution by hydrothermal method. The GQDs were synthesized under strong oxidation of concentrated sulfuric acid and nitric acid. Under N2atmosphere, The GQDs-CdSe QDs were synthesized in water solution by one-step method. The materials were characterized by UV-vis and PL. The CdSe QDs and GQDs of synthesis were employed to construct the ECL sensor, and the GQDs-CdSe QDs nanocomposites of synthesis was for the detection of ultra-trace trinitrobenzene. The whole process was characterized by cyclic voltammogram (CV) and electrochemiluminescence (ECL) analyzer. Experimental parameters such as the pH value of electrolyte solution and the K2S2O8concentration were studied. Under the same optimized conditions, the ECL intensity of GQDs-CdSe QDs nanocomposites were stronger than CdSe QDs and GQDs as the fixed electrode materials. Therefore, GQDs-CdSe QDs construct the ECL sensor for the detection of trinitrobenzene, ECL intensity decreased linearly the nitrobenzene concentrations in the range from0ppm to5ppm, with detection limit of0.58ppm (S/N=3). ECL intensity decreased linearly the TNT concentrations in the range from0ppb to50ppb, with detection limit of5.199ppb (S/N=3).This ECL sensor exhibited wide detection range, low detection limit, good reproducibility and acceptable stability. The GQDs-CdSe QDs nanocomposites extend the application of the quantum dot nanomaterials, and the QDs nanocomposites construct the ECL sensor technology to expand the field of electrochemical analysis.