| Food and environment are closely related with human survival.With the continuous improvementof material living standards,food safety,environmental pollution and other issues have become important factors that seriously threaten the health of human beings,and have received more and more attention from the public.As common substances in food processing,unreasonable and irregular use of hydrogen peroxide and nitrite not only directly harms people’s health,but also causes cancer of cells.In 2017,the World Health Organization’s International Agency for Research on Cancer listed hydrogen peroxide as a class 3carcinogen,and nitrite as a class 2A carcinogen.Therefore,sensitive and accurate detection of hydrogen peroxide and nitrite content are essential in food and environmental fields.At present,there are many methods for detecting hydrogen peroxide and nitrite,such aschromatography,spectrophotometry,fluorescence spectrometry,chemiluminescence,and electrochemical sensor methods,etc.Among them,electrochemical sensors have become the focus of scientists’research because of their unique principles and properties,providing a simple and rapid detection method for sensitive and accurate detection of hydrogen peroxide and nitrite.In this paper,a series of electrochemical sensors constructed with different magneticnanomaterials have been developed and successfully used for the electrochemical detection of hydrogen peroxide or nitrite.The conditions and mechanism for hydrogen peroxide and nitrite are discussed.And based on these,new methods for detection hydrogen peroxide or nitrite are established.Accurate detection methods provide technical support for the detection of hydrogen peroxide and nitrite in the actual food and environmental fields.The briefly descriped of the works are as follows:1.Detection of hydrogen peroxide by composite carbon nanoparticles of ferroferric oxide magnetic nanomaterialsMagnetic ferroferric oxide synthesized under alkaline conditions,and carbon nanoparticlessynthesized by microwave method are prepared by covalent bond bonding under the action of a catalyst,and the composite material is modified on a glassy carbon electrode to prepare a hydrogen peroxide electrochemical sensor and explore its electrocatalytic activity to hydrogen peroxide.The results show that the developed sensor has a good electrocatalytic performance to the reduction of hydrogen peroxide.The hydrogen peroxide concentration has a good linear relationship with its reduction current between1.00×10-6 to 1.00×10-3mol/L with the detection limit of 6.60×10-7mol/L.The method has high sensitivity,good stability with potential applications.2.Research on electrochemical sensor based ferroferric oxide composite for the detection of hydrogen peroxide and nitriteThe magnetic nanomaterials coexisting with magnetic ferroferric oxide and Prussian blue weresynthesized using FeCl3·6H2O,FeSO4·7H2O and K4Fe（CN）4,which was characterized by scanning electron microscopy and X-ray diffractometry.The electrochemical sensor was prepared by using this material.The results show that the sensor not only has good electrocatalytic reduction ability to hydrogen peroxide,but also excellent electrocatalytic oxidation performance to nitrite.Based on this,novel methods for the determination of hydrogen peroxide and nitrite were established,and the linear ranges were5.00×10-81.00×10-3mol/L and 2.00×10-82.00×10-2mol/L,respectively.The detection limits were3.40×10-8mol/L and 1.50×10-8mol/L,respectively.The sensor has good stability,reproducibility and selectivity,which can be used for the detection of hydrogen peroxide and nitrite in practial samples.3.Determin hydrogen peroxide and nitrite used iron-cobalt-doped nanomaterials loaded with gold nanoparticlesThe chloroauric acid is reduced to gold nanoparticles by using trisodium citrate,and the goldnanoparticles are composited onto the prepared iron-cobalt doping material to improve the electrical conductivity and catalytic performance of the material,and the morphology of the composite material is observed by physical characterization.The composite material was modified on a glassy carbon substrate to prepare an electrochemical sensor.The cyclic voltammetry and differential pulse voltammetry were used to determine the electrochemical performance of this sensor.Experimental results showed that the sensor have excellent electrocatalytic activities to the reduction of hydrogen peroxide and the oxidation of nitrite.The linear ranges were:5.00×10-81.50×10-3mol/L and 2.00×10-84.00×10-2mol/L,respectively,and the detection limits were 2.80×10-8mol/L and 1.20×10-8mol/L.At the same time,the recovery experiments were carried out,and the recovery rates were 96.78104.75%and 97.23103.90%,respectively.The method is sensitive and accurate,and has strong anti-interference ability,which can be successfully used for analysis and detection of hydrogen peroxide and nitrite in practical samples.4.Determination of hydrogen peroxide by hemoglobin electrochemical biosensor based on magnetic ferric oxideHemoglobin was adsorbed onto the surface of the prepared Au@Fe3O4 nanocomposite byelectrostatic action,which was characterized by SEM,EDS and XRD.An electrochemical sensor was prepared using the composite material and successfully used for the detection of hydrogen peroxide.The results showed that under the optimal experimental conditions,the linear range of hydrogen peroxide was1.00×10-62.00×10-3mol/L with the detection limit of 5.00×10-7mol/L.The sensor has lower limit,wider linear range,good stability and reproducibility,and has certain application prospects. |
PDF Full Text Request