| Nearly half a century, the incidence of cancer rises year by year. It has become more and more important in the medical field and has become a common and frequently-occurring disease. Now, cancer has become one of the leading causes of death among residents, and tumor metastasis seriously affects people’s health. The mechanism of tumor metastasis is complex and the test method is limit, so it has become important medical research problems in today’s world. Therefore we need to develop new methods which could be used in the detection of tumor micrometastasis disease.Circulating tumor cell(CTC) and tumor-specific carbohydrate antigen(CA) in blood are specific markers for diagnosing tumor micrometastasis disease. For some patients with non small cell lung cancer(NSCLC) micrometastases, the level of specific lung cancer cells A549 and CA19-9 elevated abnormally. Therefore, the level of A549 and CA19-9 in blood can be used as the basis of definite diagnosis of some non small cell lung cancer(NSCLC) patients with micrometastases.The label-free electrochemical biosensor technology has the characteristics of high sensitivity, simple operation, rapid response, miniaturization, low preparation cost and direct monitoring the reaction process between biological molecules and anti-interference of pollutants of the conjugate markers. In recent years, label-free electrochemical biosensor technology is rapidly developed and increases the researchers’ attention. The technology played increasingly important roles in genetic diagnosis, tumor markers detection and anti-cancer drug screening and so on. By combining the molecular pathology characteristics of A549 and CA19-9, we designed the several label-free electrochemical sensors for the diagnosing of A549 cell and CA19-9 in this work. The main contents are as follows:1 Constructing a label-free electrochemical cell biosensor based on GO-ECR-Con A for the detection of A549 cellsIn this section, constructing a new label-free electrochemical biosensor based on GO-ECR-Con A, [Fe(CN)6]3-/4- acting as signal system, lung cell A549 was precisely detected by electrochemical impedance spectroscopy. Using AFM characterized the GO, and employing EIS and AFM characterized preparation process of the cell sensor. Under the optional experimental condition, the linearity range was 1×102~1×106 cells·m L-1 for A549 cells, and the LOD was 21 cells·m L-1.2 Constructing a label-free electrochemical immunosensor based on PThi-SDS composite acting as signal system for the detection of CA19-9In this section, a label-free electrochemical immunosensor based on PThi-SDS composite acting as signal system was developed. Sythesised PThi-SDS composite firstly and then immobilized the GCE to detect the CA19-9 by differential pulse voltammetry in the PBS with p H 5.5. Using UV-vis and AFM characterized the PThi-SDS composite and employing EIS characterized the preparation process. Under the optional experimental condition, the linearity range of measuring CA19-9 was from 5 to 400 U·m L-1, and the LOD was 0.45 U·m L-1 for CA19-9.3 Constructing a label-free electrochemical immunosensor based on Au NPs@PThi composite acting as signal system for the precisely detection of CA19-9In this section, constructing a label-free electrochemical immunosensor based on Au NPs@PThi composite acting as signal system. Then Au NPs was immobilized on the modified electrode surface by the Au-HN2 bond which combined the anti-CA19-9. The CA19-9 was precisely detected by differential pulse voltammetry in the PBS. Using EIS characterized the preparation process. Under the optional experimental condition, the linearity range was 6.5~520 U·m L-1 for CA19-9, and the LOD was 0.026 U·m L-1. The immunosensor can detect CA19-9 in serum of different disease patients. The absolute value of standard deviation between the result and ECL was less than 11.0%. It was satisfactory. The label-free electrochemical immunosensor can measure the CA19-9 in serum in the clinical. |
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