Construction Of Electropolymerized Modified Electrode And Its Application In Biomedical Detection

Polymer modified electrode is an important branch of chemically modified electrodes.Because of their simple preparation,excellent electrocatalytic performance and good stability,they are widely studied by researchers.In this paper,a new type of functional sensor is prepared by combining polymers with different materials for the detection of drugs and hormones in the body.The detection process is quick and easy,and the results are accurate and reliable.1.Electrochemical polymerization technology is used to polymerize sulfosalicylic acid onto carbon fiber and modify it on the surface of glassy carbon electrode to construct an electrochemical sensor for theophylline.The morphology of nanocomposite was characterized by scan electron microscopy?SEM?.The polymerization between monomers was observed by Fourier transform infrared spectroscopy?FTIR?.The composite between carbon material and polymer was verified by Raman spectrum.The differential pulse voltammetry method was used to verify the poly-sulfonyl salicylic acid both carbon fiber materials can improve the sensitivity of the analyte.Under the optimal experimental conditions,the concentration of theophylline?0.6¹37?M?and the peak current value showed a good linear relationship and the limit of detection is as low as 0.2?M.In addition,the proposed sensor exhibits repeatability,stability and ease of selectivity.2.The gold nanoparticle-loaded molybdenum disulfide nanosheet material was prepared by liquid phase stripping technique and electrodeposition technique,and then the alizarin red was polymerized onto the surface of the gold nanoparticle-loaded molybdenum disulfide sheet to construct an electrochemical sensor for detecting methotrexate.The morphology of the modified electrode was observed by SEM,and the catalytic activity of the modified electrode was characterized by electrochemical technique.Under the optimal experimental conditions,the response of the modified electrode to the same concentration of methotrexate was increased by nearly 6 times compared with the bare electrode.The methotrexate concentration?0.4³8.6?M?showed a good linear relationship with the peak current value,and the detection limit was as low as0.13?M.In addition,the proposed sensor is reproducible,stable and easy to select.The content of methotrexate in the tablets was successfully detected.3.L-lysine was polymerized onto the surface of functionalized graphene-modified glassy carbon electrode by electro-polymerization,and then the laccase molecule was immobilized by cross-linking method.A highly sensitive 17?-estradiol sensor was constructed.As the laccase immobilization,glutaraldehyde was chosen as cross-linker through the group reactions.The novel enzyme sensor could recognize and determinate 17?-estradiol effectively.The morphology of the enzyme modified electrode was characterized by transmission electron microscopy?TEM?and scan electron microscopy?SEM?.The amino interaction between cross-linker and enzyme was characterized by Fourier transform infrared experimental conditions,good linear relationships were achieved in the range of 4×10^-13-5.7×10^-1111 M and a limit of detection as low as 1.3×10^-13 M.Moreover,the enzyme sensor exhibited good reproducibility,stability and high selectivity to 17?-estradiol.Excellent performance was showed in the human urine samples analysis,thus confirming great prospect for further application in clinic diagnosis and biological research.