Construction And Application Of Hydrogen Peroxide Sensor Based On Carbon Nanosphere Composites

Hydrogen peroxide（H₂O₂）as an antibacterial agent and oxidant,plays an important role in food industry,environmental detection,industrial production and other fields.At the same time,the accumulation of large amounts of H₂O₂ in the human body will cause a variety of physiological diseases,leading to DNA damage or cell apoptosis.According to the above reasons,quantitative monitoring of H₂O₂ has become an important task in various fields such as physiology,food safety and environmental governance.Therefore,we constructed two non-enzymatic electrochemical sensors for the rapid,accurate and highly sensitive detection of H₂O₂.Specific research contents are as follows:（1）Carbon nanospheres（CNs）with spherical shape and uniform size were synthesized by phenolic resin method,and their diameters mainly ranged from 275 nm to 350 nm.A non-enzymatic hydrogen peroxide sensor（Mn O₂/CNs/GCE）was constructed by a simple one-pot hydrothermal method of Mn O₂ and CNs composites.This sensor platform had good current response and catalytic performance in detecting H₂O₂,which was mainly attributed to the synergistic effect of Mn O₂ and CNs.The presence of Mn was confirmed by XPS and XRD,and the electrocatalytic reaction mechanism was studied.Mn O₂/CNs/GCE has a wide linear range of 1.00×10^-9～5.37×10^-3 M for H₂O₂,and a low detection limit of 3.33×10^-10 M（S/N=3）.In addition,the sensor can also be used for the detection of H₂O₂ in environmental water samples and beer,RSD less than 3.73%.（2）Based on the synthesis of carbon nanospheres（CNs）in above work,in this chapter,AgNPs were mainly used to replace Mn O₂,which not only solved the problem of poor conductivity of Mn O₂,but also further improved the electrocatalytic ability of H₂O₂.AgNPs/CNs/GCE sensor platform was constructed for efficient detection of H₂O₂,which AgNPs were loaded on CNs by electrodeposition method.The excellent electrical conductivity and large specific surface area of CNs can be used as good load substrate for dispersing and stabilizing AgNPs.Electrochemical experiment results showed that the sensor platform has good conductivity and high catalytic performance for H₂O₂,showing a wide linear range(4.98×10^-9～7.29×10^-3 M)and a low detection limit(1.66×10^-9 M).It has excellent selectivity to H₂O₂ in the presence of a variety of interfering substances.In addition,AgNPs/CNs/GCE sensor can be used to detect H₂O₂in makeup remover,milk and disinfectant,which has potential application value in actual analysis and detection.