Construction And Application Of CdSe/ZnS-Cy3 Biosensor

Fluorescence resonance energy transfer?FRET?means that the donor molecule transfers energy to the acceptor molecule in the form of non-radiative energy transfer,which reduces the fluorescence of the donor molecule,and enhances or quenches the fluorescence of acceptor molecule,that's a spectrum analysis technology.In recent years,the biosensor designed based on the fluorescence resonance energy transfer technology has many advantages such as low noise,high sensitivity,and strong anti-interference ability,which has attracted attention of researchers in medical?agricultural and military safety fields,and it has became one of the current research hotspots.In generally,the FRET system constructed by organic fluorescent dyes or biological proteins has poor fluorescence stability and low intensity,which greatly limits the application of the FRET sensor.Compared with traditional dyes,the quantum dots?Quantum dots,QDs?has the advantages of narrow radiation spectrum band,adjustable wavelength,high quantum yield,and low photobleaching,which is a good fluorescent material to build FRET biosensor.In this paper,CdSe/ZnS quantum dots was used as energy donor,and the fluorescent dye Cy3 was used as energy acceptor to construct prostate cancer cell biosensor to detect the fluorescence change of prostate cancer cell and the pH value of the cancer cells,external microenvironment in real time.The main research contents in this paper are as follows:1?The fluorescence resonance energy transfer system was constructed by CdSe/ZnS donor molecule and Cy3 dye acceptor molecule,then the related spectral characterization and analysis experiments were carried out.As a result,that the fluorescent quantum dots coated with amino groups?-NH₂?and the dye with carboxyl groups?-COOH?could be used to construct CdSe/ZnS-Cy3 fluorescent biosensor.At the same time,the maximum fluorescence transfer efficiency of quantum dots and dyes was quantitatively analyzed.2?Design the CdSe/ZnS-Cy3 fluorescent biosensor by using the maximum fluorescence transfer efficiency,and constructed a fluorescence monitoring system to monitor the pH value change of the external environment.The fluorescence signal intensities of the quantum dots?the dye?and the CdSe/ZnS-Cy3 system were observed when the pH value of the external environment changed.As a result,that the constructed FRET system could reflect the pH value change in real time,and the minimum detection limit was 0.19.3?CdSe/ZnS-Cy3 fluorescent biosensor was used to label the prostate cancer cells?LNCaP?,then carried out fluorescence imaging and cytotoxicity experiments.The results showed that the FERT sensor which designed in this paper had the advantages of high sensitivity,low cost,low cytotoxicity and high stability.It could be applied to early detection and imaging analysis of cancer cells in vitro.At the same time,the CdSe/ZnS-Cy3 real-time fluorescence monitoring system could quickly detect the pH value change in the prostate cancer cell microenvironment,which is convenient for patients to get timely treatment after diagnosis of prostate cancer.