| Catecholamines,as one of the chemical substances that transmit information from neuron to cell or neuron to neuron,play an important role in human regulation.Catecholamines mainly include norepinephrine,dopamine and 5-hydroxytryptamine,among which the content of dopamine is the most.Despite this,catecholamines are still present in small amounts in the human body,but abnormal changes in their levels have been linked to a range of neurological disorders,including Parkinson’s disease,schizophrenia and depression.Therefore,it is necessary to detect its content accurately and sensitively.Electrochemical sensor has been paid much attention by researchers for its advantages of rapid analysis,convenient operation and high accuracy.In this paper,acidified carbon nanotubes will be used as the substrate material to study the response of the modified electrode to dopamine,and judge whether the modified electrode can meet the experimental requirements from the aspects of anti-interference ability,stability and accuracy.Through experimental research,the modified electrode based on acidified carbon nanotubes has successfully realized the detection of trace dopamine,and at the same time has outstanding anti-interference ability,stability and accuracy.The research content is mainly divided into the following parts:（1）This paper briefly describes the structure and chemical properties of dopamine,and lists the commonly used analytical methods and their advantages and disadvantages.Then,it focuses on the kinds of electrode modification materials,and points out the current research direction of constructing modified electrode,that is,constructing modified electrode with three-dimensional morphology can improve the sensitivity of dopamine detection.（2）This paper briefly summarizes the three-electrode system for experimental detection and the principles of three kinds of electrical analysis methods.（3）The preparation of acidic carbon nanotubes and its successful drops on bare glassy carbon electrode surface,analysis of acidification carbon nanotubes modified electrodes,untreated carbon nanotubes modified electrodes and the bare electrode,the cyclic voltammetric response between the explores three electrodes in dopamine（DA）and the interfering substance of ascorbic acid（AA）and uric acid（UA）in the presence of response performance.It is found that the electrode modified with acidulated carbon tube has better electrochemical performance.The oxidation peak current and concentration of DA ranged from 2.04 μM to 10.20 μM and 10.20 μM to 22.44 μM,showing A good linear shape.The sensitivity was 11.6063 μA/ M and 4.7232 μA/ M,respectively.The detection limit LOD was 0.146 μM and 0.223 μM.The recoveries ranged from 126.27% to 116.37%.The excellent accuracy,anti-interference ability and stability of the electrode are demonstrated.（4）On the basis of acidification tubes,by adding gold nanoparticles（AuNPs）or poly(3,4-thiophene ethylene 2 oxygen（PEDOT）to study the cyclic voltammetric response of binary compound modified material,and explores the two binary modified electrodes to dopamine（DA）and the interfering substance of ascorbic acid（AA）and uric acid（UA）in the presence of response performance.It is found that the presence of gold nanoparticles can significantly enhance the catalytic activity of the modified electrode.The oxidation peak current of DA increases linearly with the concentration of DA in the range of 2.04 μM-20.40 μM,the sensitivity is 8.6972 μA/μM,and the detection limit is 0.1008 μM.Compared with the acidified CNTs/GCE electrode,it showed a lower detection limit,which can be attributed to the synergy between the acidified carbon nanotubes and gold nanoparticles.（5）Acidified carbon tube/gold nanoparticles/poly（3,4-ethylene dioxyethiophene）（acidified CNTs/AuNPs/PEDOT）modified materials were prepared by a simple one-pot method with acidified carbon tube as the substrate.The preparation method is green and simple,and the prepared ternary composite electrode is still rare at present.The cyclic voltammetry and its selective response to dopamine were investigated.It is found that the ternary modified electrode has good electrochemical performance.The oxidation peak current of DA increased linearly with the concentration of DA in the range of 9.14-29.704μM,the sensitivity was 1.539 μA/μM,the detection limit LOD was 0.286 μM,and the recovery was 95%-112.16%. |
