Construction And Application Of Porous Hollow Carbon Nanosphere Composites Electrochemical Sensor

With the gradually increasing awareness of people's health,the demand has grown rapidly for selecting a method to sensitive detect target in recent years.Because of the advantages of easy operation,stable performance,and high sensitivity for analytical targets,electrochemical sensors are widely used in the fields of food detection,environmental analysis and clinical diagnosis.The performance of electrochemical sensors has a close relationship with the electrode modification materials.Porous hollow carbon nanospheres and their composites can be used as the electrode modification materials of sensors due to the performance of low cost,large specific surface area,good stability,excellent conductivity and high porosity.In this work,two kinds of sensors were constructed to sensitively detect nitrite and superoxide anion.The main contents are as follows:?1?A nitrite electrochemical sensor was constructed with porous hollow carbon nanospheres as the electrode modification material.The morphology and structure of the synthesized materials were characterized by scanning electron microscopy?SEM?,transmission electron microscopy?TEM?,nitrogen adsorption desorption?BET?and fourier transform infrared spectrometer?FT-IR?.At the same time,the electrochemical behavior of nitrite was studied by cyclic voltammetry and amperometry.The constructed sensor showed high electrocatalytic activity for nitrite oxidation,high sensitivity(275.7?A·mM^-1·cm^-2),wide linear range?0.037–6950?M?,and low detection limit?0.01?M?.In addition,the sensor was applied to detect nitrite in pickle,and the scavenging capacity of different antioxidants to nitrite was also explored.The sensor has potential applications in food detection.?2?Gold nanoparticle/chitosan-porous hollow carbon nanosphere composites were prepared by modifying the porous hollow carbon nanospheres,which were used to construct superoxide anion(O₂^·-)electrochemical sensor.Due to the large specific surface area,excellent electron conduction rate and electrocatalytic performance,the sensor showed a wide linear range and low detection limit for O₂^·-detection.Moreover,we studied the process of sodium fluoride?NaF?as a stimulant to stimulate cancer cells?Hela cells?.It shows that the amount of superoxide anions released by the cells is closely related to the amount and the action time of NaF.At the same time,the scavenging ability of different antioxidants to superoxide anions was explored.This work is of great significance for evaluating the metabolic processes of superoxide anions in organisms.