Preparation Of Carbon Nanotube Composites And Electrochemical Determination Of Biomolecules

With the changes of the times and the advancement of science and technology,many detection methods have emerged and can be used in biology.Electrochemical detection analysis has attracted much attention in various research fields due to its advantages of rapid detection and sensitivity,and has been widely used.Among them,animals,plants and humans coexist and are closely related to each other in nature.Therefore,the protection of organisms and the environment is very important.At present,there are many methods to detect trace active molecules in animals and plants.Compared with traditional methods,electrochemical detection methods have the advantages of simple operation,rapid response and good detection effect,which can greatly save cost and time.favored by researchers.In this paper,carbon nanoparticles were prepared by a one-step hydrothermal method,and then composited with carbon nanotubes.Then,the residues on the surface of carbon nanoparticles were used as monomers to form a polymer film by electrochemical methods.The properties of the composites were studied by various characterization methods.The complex-modified electrodes are used to detect bioactive molecules.The main contents include the following aspects:1.Nitrogen-boron-doped carbon dots(CDs)were prepared by hydrothermal method with melamine as carbon source and boric acid as dopant.A novel polymelamine-carbon dots-carboxylated multi-walled carbon nanotube composite was prepared by electropolymerization using CDs-immobilized melamine residues as monomers in chloride ion solution,and the composite modified electrode was used for simultaneous detection Ascorbic acid,dopamine and uric acid.Ascorbic acid has no linear relationship between 200～1600 μM,dopamine and ascorbic acid have good linear relationship between 0.1～10 μM and 0.1～200 μM,respectively,and the minimum detection limit is 0.023 μM(S/N=3)and 0.064 μM(S/N=3).And there is a good recovery rate in the actual sample.2.Chitosan carbon nanoparticles(CNPs)were prepared by a simple hydrothermal method using chitosan(CS)as carbon source,and then ultrasonically treated with multiwalled carbon nanotubes(MWCNTs)to obtain CPNs-MWCNTs composites.Using CNPs-immobilized chitosan residues as monomers,a composite of chitosan film(CSF)-CPNs-MWCNTs and CuNPs was obtained by co-electrodeposition in copper ion solution.Simultaneously sensitive determination of SA,the detection range is 0.01～50μM and 4～30 μM,respectively,the detection limit is 8.6 n M(S/N=3)and 0.7 μM(S/N=3),respectively,with good stability,anti-interference and reproducibility.At the same time,compared with high performance liquid chromatography,it has better accuracy and recovery,and can be used in the detection of actual samples.3.Firstly,platinum nanoparticles(Pt NPs/GCE)were deposited on the surface of glassy carbon electrode by electrodeposition method.Saffron carbon nanoparticles(STNPs)were prepared by a simple hydrothermal method,and ultrasonically mixed with MWCNT-COOH(MWCNTs-COOH)to obtain STNPs/MWCNT-COOH composites,which were then added dropwise to Pt NPs/GCE to obtain Pt NPsSTNPs/MWCNT-COOH/GCE,using STNPs-immobilized saffron residues as monomers,and finally putting them into a solution of 0.1 M PBS(p H=7)for electropolymerization to obtain the final composite modified electrode Pt NPs-poly Saffron(PST)-STNPs/MWCNT-COOH/GCE.It is used for the detection of luteolin,and it has a good linear relationship between 0.001～10 μM,and the detection limit is0.57 n M(S/N=3),which has better accuracy than high performance liquid chromatography.sex.At the same time,it has good anti-interference,stability and reproducibility,and can be used for the detection of luteolin in peanut shells of actual samples.Conclusion : The electrochemical detection of active molecules that can affect the normal growth of animals and plants is the further development of the detection of bioactive molecules,which can provide more ideas and means for the detection of biological molecules.It can not only promote the development of agriculture,but also benefit people’s health.