Construction And Application Of Electrochemical Biosensors Based On Functional Materials

The integrated development of recognition and electronic components is the research hotspot of electrochemical sensors and biosensors.Various kinds of electrochemical devices,such as amperometric sensors,electrochemical impedance sensors,electrochemical luminescence sensors,and photoelectric chemical sensors,provide a variety of recognition and signal output strategies based on electrochemical changes at the electrode interface.These methods are widely used in chemical and biological target detection because of their strong specificity,stability and sensitivity.With the development of nanotechnology and nanoscience,electrochemical signal amplification based on nanomaterials has great potential in improving the sensitivity and selectivity of electrochemical sensors and biosensors.Nanomaterials,especially functionalized nanomaterials,have multiple active groups on the surface and have effective fixed sites,which can be used as carriers of signal markers.It also has high specific surface area,excellent catalytic activity and electrical conductivity,and can also participate in the construction of a stable and sensitive electrochemical sensing platform.Modified nanomaterials can optimize and improve the advantages of raw materials such as catalytic activity,biocompatibility,chemical stability,high selectivity and high conductivity,breaking through the functional barriers of original single materials in some aspects and generating synergistic effects.Some natural molecules in the biological body may be used as the diagnostic basis of diseases,especially in some major malignant diseases,such as tumor,so early and timely diagnosis is of more important significance.Among them,studies have shown that DNA methylation of DNA transferase is one of the possible causes of cancer and genetic diseases.Detection of DNA methyltransferase is of great significance to the diagnosis and treatment of cancer diseases.In this paper,by preparing a series of high-performance conductive nanocomposites,new DNA biosensors have been prepared.Compared with other methods,such as spectroscopy and chromatography,electrochemical measurements are cheaper,simpler and easier to miniaturize,which makes them more suitable for detection.1.A graphene-modified electrochemical DNA biosensor was prepared to detect the presence of methyltransferase.The biosensor using the Cp G methylation transferase can catalytic DNA sequence of cytosine methylation,DNA nucleotides acid in methylation sensitive restriction endonuclease was unable to complete the catalytic,graphene material can’t combine to the electrode surface,which reduces the sensor electronic transport capacity,the electrode impedance increase.The sensor modifies the surface of the gold electrode with only one DNA sequence during the whole process.The rest of the reactions were carried out on the surface of the gold electrode.The system is relatively stable,the operation is simple,and the detection limit can reach 0.7 U/m L.And it doesn’t require any other modifications to the DNA.2.Infinite coordination polymer nanoparticles of iron were prepared by oxidation of ferrocene with potassium permanganate.By introducing sodium dodecyl benzene sulfonate surfactant micelle as the reaction template,the concentration of various substances in the reaction system was changed to get the spherical nanoparticles.Scanning electron microscope,scanning electron microscope energy spectrometer and other instruments were used to optimize the characterization.Under the condition of 7m M sodium dodecyl benzene sulfonate,1.5mm potassium permanganate and 1m M ferrocene nanometer in the reaction system,the particle size obtained is about 200 nm,and has regular spherical shape.It provides a new method for the synthesis of coordination polymer rice particles.