Study On Nanochannels Immunosensing Platforms Based On Electrochemical Characteristics Of C₆₀

Due to the combination of the specific recognition of antibody-antigen and the high sensitivity of electrochemical methods,electrochemical immunosensing has achieved significant progress in the early diagnosis of cancer and other major diseases.In this thesis,based on electrochemical characteristics of C₆₀fullerene,two carbon nanomaterials-based modified electrodes were prepared to construct two electrochemical immunosensing platforms based on nanochannels for the determination of human epididymis protein 4 and carbohydrate antigen 125,respectively.The studies provided a novel perspective for the development of electrochemical biosensing platform and supplied a reference for the early diagnosis of ovarian cancer.The main contributions of the thesis are listed as follow:1. It was discovered for the first time that K₃[Fe?CN?₆]had a dramatic enhancement effect on the peak current occurred on C₆₀-TOAB-GE/GCE and the enhancement mechanism was revealed.The enhanced redox peak was attributed to the redox of the ternary ion pair association complex C₆₀-TOA⁺-[Fe?CN?₆]^3-.Combining this special character of C₆₀-TOAB-GE/GCE and using[Fe?CN?₆]^3-as a reporter,an immunosensing platform based on AAO nanochannels was constructed for the determination of human epididymis protein 4.A linear range from 1.0 ng·m L^-1to 100 ng·m L^-1and a low detection limit(0.2ng·m L^-1)were achieved.The platform not only exhibited a good repeatability and reproducibility,but also can detect target without labeling.2. A modified electrode based on Prussian blue-C₆₀nanocomposite was developed and its electrochemical behavior was studied.As result:Also using[Fe?CN?₆]^3-as a reporter,the ratiometric nanochannels immunosensing platform for the detection of CA125 was achieved on the basis of the I_PB/I_Trivariation caused by redox current change of Prussian blue and C₆₀.The variation was depended by the change of flux of K₃[Fe?CN?₆]into the nanochannels.The platform featured a linear calibration range from 1.0 U·m L^-1to100 U·m L^-1with a low detection limit of 0.1 U·m L^-1.A label-free ratiometric nanochannels immunosensing platform was proposed for the first time,which can overcome the influence of the detection environment on the accuracy and stability of the results and improve the accuracy of the target detection.