Studies On Chemiluminescence Detection Of Cancer Cells Based On Nanoprobe Technology

The tumor, one of the malignant diseases, is a serious threat to human life and health. So far, many researches and control data have indicated that early diagnosis and early treatment is an effective way to prevent tumor and reduce mortality. Chemiluminescence (CL) analysis has many advantages, such as high sensitivity, simple instrumentation, widely linear range and automatic and so on. So it has attracted more and more attention by researchers. In this paper, a new strategy for cancer cells detection is developed based on electrochemiluminescence (ECL) and flow-injection chemiluminescence (FI-CL) based on nanoprobe technology. Moreover, the feasibility of this assay is evaluated by detecting Ramos cells spiked in complex samples and human blood samples. The main jobs of this thesis can be concluded as follows:1. The study of electrochemiluminescent (ECL) detection of cancer cells based on nanoprobe technologyThe method successfully labels [Ru(bpy)₂(dcbpy)NHS] to Au-Fe₃O₄ shell-core magnetic nanoparticles (Au@Fe₃O₄) to fabricate the bio-bar-code DNA signal probe, which is employed to highly sensitive ECL detection of cancer cells based on high specificity and affinity of cell aptamers for the recognition of unique molecular signatures on the surface of cells. The linear range for the detection of Ramos cells is from 103 to 105 cells with a good reproducibility. In addition, by using a magnetic gold electrode, the signal probe was directly captured onto the surface of electrode with simple operation and a low cost. 2. The study of Luminol-H₂O₂-Co²⁺ flow injection chemiluminescence (FI-CL) systemThe CL intensity of Luminol-H₂O₂-Co²⁺ FI-CL system is affected by many factors. In this system, the detection conditions of Luminol-H₂O₂-Co²⁺ FI-CL system are optimized: the concentration of Luminol solution is 5.0×10^-4 M; the concentration of H₂O₂ solution is 1.0×10^-3 M and the pH of Co²⁺ solution is 4. Under the optimum conditions, the Luminol-H₂O₂-Co²⁺ CL mechanism has been preliminary proposed.3. The study of FI-CL detection of cancer cells based on nanoprobe technologyThe CoNPs have been successfully prepared with an average diameter of ⁴ nm, which then are successfully labeled to Au-Fe₃O₄ shell-core magnetic nanoparticles (Au@Fe₃O₄) as a bio-bar-code DNA signal probe. Under the optimal experimental conditions, a novel strategy for highly sensitive detection of cancer cells is developed based on Luminol-H₂O₂-Co²⁺ FI-CL system by the high specificity and affinity of cell aptamers for the recognition of unique molecular signatures on the surface of cells. The linear range for Ramos cells is from 10³ to 10⁵ cells with a good reproducibility.