Detection Of Tumor Related Biological Molecules Based On F(?)ster Resonance Energy Transfer

Tumor is a new organism in the body formed by the abnormal proliferation of cells under the influence of various factors. At present, according to the harm to human body and the new biological characteristics of the cells, the tumor is classified into benign and malignant. Malignant tumor grows rapidly, is easy to be transferred, and the rate of recurrence is very high. It has been one of the most serious diseases that endanger human health. So it is very important to monitor, detect and treat tumor in clinic. In this thesis, optical biosensors with good stability, high specificity and low sensitivity for detection of tumor related biological molecules were established by using the special optical properties of conjugated polymer brush, thioflavin T and gold nanoparticles.Firstly, conjugated polymer brush(ThNI)/aptamer(apt29)/ThT complex was established as a research system, a novel Fo?ster resonance energy transfer sensing mechanism based on ThNI and ThT was designed for the detection of thrombin. Thrombin can induce the formation of G-quadruplex, because of the larger steric hindrance of thrombin, the FRET is more inefficient than that without thrombin. The minimum detection limit of thrombin in the buffer solution and 10% serum was 0.2 nM.Secondly, ThT was used as the sensing material of fluorescence signal, gold nanoparticles as colorimetric signal sensor material. Using Th T can specially induce the G-rich DNA to form a G-quadruplex and inset G-quadruplex with strong fluorescence to construct a new fluorescence-colorimetric sensor for the detection of tumor associated DNA sequences. Because of above characcter, the configuration of G-rich DNA changed, so it cannot adsorbed on the surface of AuNPs, AuNPs aggregation and color change after adding salt. The sensor can detect the G-rich DNA sequence in a small range of 5 nM-300 nM, and the minimum detection of limit is 5 nM.Finally, AuNPs was introduced into the detection of tumor marker(PSA),its physical adsorption to FITC-peptide and its aggregation phenomenon after FITC-peptide been cut were used to construct a "turn-on" fluorescence-colorimetric sensor. When PSA was existed, the PSA cleaved the labeled peptide specially, small fragments of oligopeptide had weak interaction with gold nanoparticles, not as a "bridge" draw the distance between the gold nanoparticles closer, so the fluorescence of FITC recovered and the color of gold nanoparticles unchanged. The minimum detection of limit of PSA in the buffer solution is 0.01 nM, and in 10% serum is 0.05 nM.