Application Of Electrochemical Sensor Based On Amino-reduced Graphene Oxide In Heavy Metal Ion Detection

The environmental pollution caused by heavy metals is becoming more and more serious,and human health and environmental protection are facing huge challenges.Because heavy metals have the characteristics of high biological toxicity and difficult to degrade,if the human body ingests too much heavy metals,it will damage or even change the protein structure in the human body,affect the cell function,and then cause various diseases that are not easily cured.Among them,the environmental impact of lead and cadmium pollution is particularly serious.Therefore,accurate and fast analysis and detection of lead ions and cadmium ions can greatly improve the effect of treating heavy metal pollution.This paper uses electrochemical detection technology,the NH₂-r GO is regarded as basal material,designing and preparing composite materials.The composite materials are modified on the bare glassy carbon electrode to build a series of electrochemical sensors,realizing high sensitivity,long term stability and repeatability detection of the lead ion and cadmium ion.1.Amino-reduced graphene oxide/gold nanocomposites/glutathione?NH₂-r GO/Au NPs/GSH?were prepared with amino-reduced graphene oxide as the substrate material,and the composite materials were characterized by scanning electron microscopy,infrared spectroscopy and XPS.Then,the composite materials were modified on glassy carbon electrode.Combining with the bismuth membrane method,we constructed the electrochemical sensor of Bi/NH₂-r GO/Au NPs/GSH.The electrochemical sensor of Bi/NH₂-r GO/Au NPs/GSH could detect Cd²⁺and Pb²⁺with high sensitivity and selectivity.There was a good linear relationship between the stripping peak current and concentrations of lead ion and cadmium ion,and the linear range of Cd²⁺and Pb²⁺was 1-120?g/L,the detection limit of Cd²⁺was 0.09?g/L?S/N=3?,the detection limit of Pb²⁺was 0.38?g/L.The results showed that Bi/NH₂-r GO/Au NPs/GSH was a good modified material for detection of Cd²⁺and Pb²⁺in water.2.The amino-reduced graphene oxide/chitosan composite materials?NH₂-r GO/CS?were synthesized by ultrasound and stirring,and the electrochemical sensor of Bi/NH₂-r GO/CS/GCE was constructed in combination with the bismuth membrane method,realizing the high sensitivity detection of Pb²⁺by differential pulse anodic stripping voltammetry?DPASV?.The detection linear range was 2-150?g/L,and the detection limit was 0.26?g/L.3.On the basis of the detection of Pb²⁺by electrochemical sensor of Bi/NH₂-r GO/CS/GCE,changing the the ratio of amino-reduced graphene oxide and chitosan,the amino-reduced graphene oxide/chitosan composite materials?NH₂-r GO/CS?were synthesized by ultrasound and stirring.The composite materials were modified on glassy carbon electrode,then glutamic acid was modified on the electrode by cyclic voltammetry to build the electrochemical sensor of NH₂-r GO/CS/Glu/GCE for detecting trace Cd²⁺and Pb²⁺at the same time.The linear range of Cd²⁺and Pb²⁺was 2-100?g/L,the detection limit of Cd²⁺was 0.47?g/L and the detection limit of Pb²⁺was 0.32?g/L.