| In recent years,environmental pollution,food safety,and so on have become increasingly prominent with the development of science and technology,causing widespread concern.Water pollution,soil pollution,excessive use of food additives,and so on will not only seriously endanger human health but also undermine our ecosystem.Therefore,the establishment of rapid and sensitive detection method is of great significance for the environmental monitoring and food safety issues.Nitrite（NO2-）and hydrogen peroxide（H2O2）are widely used in food,environment,medicine and industry,besides,are an indispensable part of ecosystem.In addition,excessive nitrite or hydrogen peroxide not only can cause human poisoning but also has great harm for the environment.So,the development of sensitive rapid and simple detection methods for the detection of nitrite and hydrogen peroxide is particularly important.Carbon nanomaterial as a popular nanometer materials,have been favored by more and more researchers because of its good biocompatibility,low toxicity,simple preparation and other advantages.In this paper,a series of excellent electrochemical sensors are built based on carbon nanoparticles（CNs）which realize the detection of nitrite and hydrogen peroxide,and achieved satisfactory results.The works were as follows:1.Researches on horseradish peroxidase biosensors based on carbon nanocomposite modofied withgold nanoparticlesA highly sensitive peroxidase biosensor was developed successfully through immobilizing horseradish peroxidase into nanocomposite composed of multiwalled carbon nanotubes/carbon nanoparticles and gold nanoparticles,which was characterized by TEM,FT-IR and electrochemical techniques.The experimental results indicated that this novel biosensor gave an excellent linear relationship between the peak current of H2O2 and its concentration in the range of 2.9×10-69.8×10-4 mol/L with the detection limit（3N/S）of4.8×10-7 mol/L.This new method is simple and rapid with a pretty good result.2.A novel electrochemical sensor based on carbon nanoparticle composite films for thedetermination of nitrite and hydrogen peroxideAn electrochemical sensor for the determination of nitrite and hydrogen peroxide was prepared by successive electropolymerization carbon nanoparticles,doped multiwalled carbon nanotube and chitosan on the surface of glassy carbon electrode（GCE）.The carbon nanoparticles were characterized by Transmission electron microscopy（TEM）,Fourier transform infrared spectroscopy（FT-IR）and X-ray diffraction（XRD）,and have a further dissection on NO2-and H2O2 sensing.The results showed that CS/MWCNT/CNs/GCE had good electrocatalysis for the detection of nitrite and hydrogen peroxide,the peak current increased linearly with the nitrite and hydrogen peroxide concentration in the range of 5.0×10-61.0×10-3 mol/L and4.0×10-65.0×10-4 mol/L with the detection limits of 8.9×10-7 mol/L and 6.6×10-7 mol/L,respectively.And it also showed good reproducibility and stability.3.Determination of nitrite and hydrogen peroxide using a novel sensor based on carbon dots,polydopamine and grapheneIn this work,carbon nanoparticles-based composites were synthesized using carbon nanoparticles,polydopamine and graphene by hydrothermal method.The novel sensor was modified with the carbon nanoparticles-based composites,which was used for the simultaneous determination of nitrite and hydrogen peroxide,and the composites were characterized by Scanning electron microscopy（SEM）.Experiment proved that the sensor had good electrochemical response on the detection of nitrite and hydrogen peroxide.Nitrite and hydrogen peroxide in the concentration range of 8.0×10-71.0×10-3 mol/L and 1.0×10-61.0×10-2 mol/L had a good linear relationship with its current,respectively.And the detection limits of nitrite and hydrogen peroxide were 9.7×10-9 mol/L and 1.4×10-7 mol/L.The current of nitrite onlydecreased 8.09%after continuous scanning for 100 cycles,which indicated the good stability,and itspotential application value.4.Sensitive determination of hydrogen peroxide and nitrite based on Au/CNs/Fe3O4NanocompositesA highly sensitive sensor based on carbon nanoparticles/Au/Fe3O4 nanocomposites was constructed,obtained the novel sensor with chitosan as the protective film.The composite was characterized byscanning electron microscopy and energy spectroscopy.The experimental results displayed that the nanometer electrochemical sensor has a good catalytic effect on the oxidation of NO2-and the reduction of H2O2,and a new method was established for simultaneous detection of H2O2 and NO2-.The current of H2O2 and NO2-were linearly related to their concentrations in the range of 8.0×10-71.0×10-2 mol/L and7.0×10-71.0×10-3 mol/L,respectively.The detection limits were 1.1×10-8 mol/L and 7.1×10-9 mol/L.At the same time,the sensor has a good reproducibility and selectivity. |
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