Construction And Application Of Electrochemical Sensor Based On Doped Graphene Quantum Dots

This article explores the doped quantum dots to modify the work electrode used in electrochemiluminescence technology and constructs related ECL sensors,studies the nanoluminescence of nitrogen-doped graphene quantum dots and nitrogen-sulfur-doped graphene quantum dots.The related performance of the material,the successful detection of salicylic acid,copper ions and ascorbic acid and other substances,the construction of a new electrochemical luminescence sensor,on the one hand,enriches the types of new graphene quantum dots,on the other hand,it also explores the wider application of GQD's ECL value has laid the foundation for its further development.In Chapter ?,the development and application of electrochemiluminescence technology,quantum dots,graphene quantum dots and doped graphene quantum dots were summarized.The main development fields and current situation of the three are described in detail.A new idea of developing a new sample analysis system was proposed based on the advantages of the three,which will pave the way for the subsequent experiments.In Chapter ?,nitrogen-doped graphene quantum dots(N-GQDs)were synthesized.Compared with pure GQDs,the electrochemiluminescence(ECL)signal was significantly enhanced.Salicylic acid(SA)was selected as the target detection substance,and a molecularly imprinted electrochemiluminescence sensor was constructed to achieve the separation and detection of SA.In Chapter ?,nitrogen-sulfur co-doped graphene quantum dots(NSGQDs)were synthesized.Compared with N-GQDs,the electrochemiluminescence(ECL)signal was greatly enhanced.A novel NSGQDS ECL sensor was constructed and used for the detection of Cu²⁺.Under the action of external voltage,NSGQDs transition from ground state to excited state,and release light energy in the process of returning to ground state.After the addition of Cu²⁺,Cu²⁺and NSGQDs complex,so that the excited NSGQD decreased,showing ECL signal quenching,the higher the concentration of Cu²⁺,the greater the degree of quenching.The quenching effect of Cu²⁺on NSGQDs was used to realize the selective rapid and sensitive detection of copper ions in industrial wastewater This study lays a foundation for the rapid detection of heavy metal ions in actual samples and broadens the application of nanomaterials in the field of electrochemiluminescence sensing.In Chapter ?,based on the excellent electrochemiluminescence characteristics of NSGQDs,a quenching-recovery ECL sensor for the highly sensitive detection of ascorbic acid(AA)was constructed by further modification of Cu-MOF on the surface of the gold electrode.Due to the presence of a large number of amino groups on the surface of NSGQDs,when Cu-MOF is present,Cu(II)in Cu-MOF interacts with NSGQDs to form Cu(II)-NSGQDs complex,leading to ECL signal quenching of NSGQDs.After adding AA,AA reduces Cu(II)bound on the surface of NSGQDS to Cu(I),thus removing Cu-MOF from the surface of NSGQDS.The method was successfully applied to the determination of ascorbic acid in blood samples,and the pharmacokinetics of ascorbic acid in human blood for 24 h were further studied.