Graphene Based Nano Particle Modified Electrode For Cadmium Ion Detection

In recent years,heavy metal pollution incidents have occurred repeatedly.Cadmium ion is a kind of highly toxic heavy metal ion,that is continuously enriched in the biological chain or environmental circulation.Once it enters the human body,it is difficult to metabolize,posing a great threat to human life and health.And the marine environment matrix is complex,with many interference factors,and detection difficulties.Therefore,it is of great practical importance to explore an efficient,sensitive and accurate method for detecting cadmium ions.In this paper,based on the electrochemical three-electrode detection theory,a scheme for detecting cadmium ions by cyclic voltammetry（CV）and square wave anodic stripping voltammetry（SWASV）is given.The characteristic of the scheme is that the composite graphene,ferric oxide and chitosan are used to prepare the selectively enhanced electrode modification material of cadmium ion by synergistic action.Subsequently,a new GR/Fe₃O₄/CS/GCE electrode was obtained by modifying the electrode surface with the drop coating method,which laid a foundation for the study of sensor performance.The experimental conditions such as electrode modification amount,supporting electrolyte type,p H value,deposition potential and deposition time were optimized by single factor experiment and orthogonal experiment.And the experimental process was scientific and standardized.Under the optimal experimental conditions,the cadmium ion detection research was carried out based on GR/Fe₃O₄/CS/GCE.The experimental results show that the concentration of cadmium ions has a good linear relationship with the dissolution peak current value in the range of 2～180μg·L^-1,the correlation coefficient is 0.997,the detection limit of cadmium ions is 0.54μg·L^-1,GR/Fe₃O₄/CS modified electrode realizes the rapid detection of cadmium ions with high selectivity and sensitivity.Finally,GR/Fe₃O₄/CS/GCE was applied to detect the cadmium ion content in the coastal seawater of Qinzhou Port,Guangxi.The detection results were basically consistent with those of the ICP-MS method,and the recovery rate of the standard addition experiment was between 92.1%and 105.4%,indicating that the detection accuracy of this modified electrode is high,providing a new choice for the detection of cadmium ion content in water quality,and has certain application value.