Using Molecular Marker Technology And Sensor Technology To Detect Carcinoembryonic Antigen

Carcinoembryonic antigen(CEA) is a kind of tumor marker, it can reflect the existence of a wide variety of tumor. In recent years, as a marker of colorectal cancer, gastric cancer, breast cancer and lung cancer, more attention paid to the research on its detection methods. In general, the detection methods of CEA include that serum CEA detection, the pathological tissue CEA immunohistochemical staining, the pathological tissue RT-PCR and so on. But the method of using photoelectric sensor to detect the concentration of CEA is rarely. While the photoelectric sensor has been widely used in today, as it has the characteristics of simple and sensitive. This article will attempt to build a new type of CEA sensor, by using the change of photoelectric properties of the sensor to reflect the concentration of CEA in solution, to explore a more efficient and convenient detection method of CEA. Mainly contains two aspects in this article, through the interaction between mercaptan-AuNPs and CEA, and explore the relationship between response signal and the concentration of CEA. Another content is that by using CEA immune sensor to detect the concentration of CEA, through the change of photoelectric characteristics of sensor to reflect the concentration of CEA.1. Using of mercaptan-AuNPs interact with CEA, explore the relationship between response signal and the concentration of CEA. Gold nanoparticles is a kind of nano material, it has many excellent properties, in this experiment, by using of two kinds of mercaptans to modify gold nanoparticles, two different kinds of mercaptan-AuNPs had been obtained. And use them to interact with CEA, explore the relationship between response signal and the concentration.Results show that by using ethyl mercaptan and dodecanethiol modified gold nanoparticles, the detection sensitivity has a good ascension. Especially is the dodecanethiol-AuNPs, not only enhances the sensitivity of detection, and shows a good regularity, namely the change of fluorescence intensity and the concentration of CEA has obvious negative correlation.Because of these two kinds of new nano materials have no specificity to CEA, thus we have studied the interaction between nano materials and IgG/ protoporphyrin.2. Using CEA immune sensor to detect the concentration of CEA, through the change of photoelectric characteristics of sensor to reflect the concentration of CEA. The building method of sensor is that, the gilded ITO conductive glass as the solid substrate, on the surface in combination with IgG-Au NPs.Adopted three methods to characterize the change of the sensor, ultraviolet-visible spectrophotometry, cyclic voltammetry and electrochemical impedance spectroscopy, the results show that the change of optical and electrochemical properties of sensor and concentration of CEA, there is a significant linear relationship between them, the linear range is 5-80ng/ml. We have got three standard curves between the concentration of CEA and the signal of sensor.