Preparation Of Boron-doped Diamond Film Electrode And Electrochemical Trace Detection Of Aflatoxins

Diamond is the hardest material in nature,and it has excellent properties such as wide band gap,high heat conduction and wide potential window.It has a very wide range of applications in machinery,electronics,aerospace and other fields.In this paper,the self-supporting diamond films were prepared by chemical vapor deposition?CVD?method on copper mesh,and their wettability was studied.A uniform layer of gold nanoparticles was modified on the surface of boron-doped diamond?BDD?by ion sputtering and thermal oxidation,and the detection of aflatoxin B₁?AFB₁?at low concentration was realized by combining with aptamer.Main resultsare as follows:?1?The influence of self-supporting CVD diamond film,hydrogen terminal and oxygen terminal on the wettability of diamond surface was studied.The results show that the hydrogen terminal is hydrophobic and the oxygen terminal is hydrophilic.The conversion between hydrophilic and hydrophobic diamond films can be realized by hydrogen etching and oxygen etching.?2?Boron-doped diamond?BDD?films were grown on p-type silicon by microwave plasma CVD as electrochemical electrodes.A layer of Au-NPs was uniformly coated on the surface of BDD film by ion sputtering and thermal oxidation.The aptamer was modified by Au-S bond on the BDD electrode,and then 6-mercapto-1-hexanol?MCH?was used to block the redundant blank active sites on Au-NPs to prepare the MCH/Aptamer/Au-NPs/BDD aptasensor with specificity for aflatoxin B₁ detection.The aptasensor has many advantages,such as high sensitivity,specificity,repeatability,stability and wide dynamic detection range.The detection limit can reach5.5×10^-14 mol L^-1.The aflatoxin B₁ in peanut was successfully detected by this sensor,and the recovery rate was high.In this paper,diamond films are grown on copper mesh structure,and their surface wettability is changed by the change of hydrogen terminal and oxygen terminal.Based on conducting diamond electrode,MCH/Aptamer/Au-NPs/BDD aptasensor was prepared.The aptasensor has many advantages,such as low detection limit,strong specificity,high sensitivity,good stability and wide dynamic detection range.It can be used in many fields for low concentration detection of harmful substances,and has a very broad application prospect.