Preparation Of Metal-carbon-based Nanomaterials And Their Electrochemical Sensing Detection

Highly active electrochemical sensing catalysts have received a lot of attention from researchers because of their high stability and low price.However,it remains challenging to add specific active sites,to accelerate the decisive step of catalysis of the substance to be detected,and to increase the electrochemical catalytic activity,which significantly limit the overall performance of electrochemical sensing.Metal-carbon-based structured nanomaterials have the advantages of high sensitivity and specificity,easy size tuning,fast response time,and low cost in electrochemical sensing detection.Based on this,three metal-carbon-based nanomaterials are constructed and their enhanced mechanisms for electrochemical sensing detection are investigated in this paper,as follows:（1）In this work,the preparation of copper-cobalt-based organic backbone（Co/Cu-MOF）and hydroxyl adsorption induced reactive oxygen species to enhance the electrochemical glucose sensing performance were carried out.A copper-cobalt-based organic backbone（Co/Cu-MOF）with excellent sensing performance was designed based on the nanostructure of"ultramicroelectrode",and copper and cobalt ions were introduced by hydrothermal method using dimethylimidazole as the starting substrate to prepare a copper-cobalt-based organic backbone（Co/Cu-MOF）with good electrochemical glucose sensing performance.It was found that Co/Cu-MOF（20:1）showed the best OER performance in Co/Cu-MOF（4:1）,Co/Cu-MOF（10:1）and corresponded to the best electrochemical glucose sensing performance with a sensitivity of 0.45 m A m M^-1 cm^-2 and LOD of 0.82μM.In this work,it is proposed that the change of cobalt species may affect its ability to adsorb hydroxyl groups during the OER reaction,thus changing the performance of electrochemical sensing of glucose,which provides new ideas for the subsequent design of new electrochemical glucose electrochemical sensors.（2）To further investigate the speculation that modulating the ability of cobalt species to adsorb hydroxyl groups can modulate the sensing signal of glucose oxidation process,experiments on Cu Co-NCNTs structured nanomaterials were designed in this work to further verify.First,this work prepared Cu Co-NCNTs structured nanomaterials by hydrothermal synthesis,programmed heating and calcination,and applied them to explore the enhancement mechanism of glucose electrochemical sensing detection.After the study,in Cu-Co double active site carbon nanotubes,copper acts as the main active site for glucose electrochemical sensing,and cobalt acts as the active site for adsorption of hydroxyl groups to provide oxygen source for copper-catalyzed glucose,i.e.,the Cu-Co double active site synergistically promotes the provision of oxygen source and electron transfer,resulting in better glucose electrochemical catalytic performance of Cu Co-NCNTs with a sensitivity of 0.84 m A m M^-1 cm^-2,and the detection limit was 1μM.This study proposes that the active hydroxyl groups derived during the catalytic process provide the oxygen source for glucose oxidation and promote the oxidative catalytic activity of glucose.This idea not only provides new ideas for the analysis of glucose oxidation,but also helps to design new non-enzymatic electrochemical sensors with excellent performance.（3）Based on the excellent electrochemical sensing performance of metal-carbon-based nanomaterials,this work prepared nickel-cobalt-based carbon nanosheets（Ni Co-CNs）with good electrochemical dopamine sensing performance by hydrothermal introduction of cobalt and nickel atoms using dimethylimidazole as the starting substrate,and the electrochemical dopamine sensing sensitivity was 33.85μA m M^-1 cm^-2 and LOD was 367μM.This study proposed the structure of nitrogen-doped carbon nanosheets in the catalytic process,which promoted the oxidative catalytic activity of dopamine.This idea not only provides a new idea for analyzing the oxidative processivity of dopamine,but also helps to design a new dopamine electrochemical sensor with excellent performance.