| The main idea of the reseach was to explore novel and sensitive biosensors for the detection of cancer cells and their makers based on chemiluminescence technology,electrogenerated chemiluminescence technology coupling the signal amplification and DNA hybridization technology.It provided a basic theoretical reseach for clinic diagnoses of many diseases at early stage.This paper contained five chapters:Chapter 1,Introduction.This chaper introduced cancer cells and their makers,and also introduced their detection methods and their develop trend,especially signal amplification,chemiluminescence technology and electrogenerated chemiluminescence technology.Chapter 2,Design of electrogenerated chemiluminescence detection of thombin based on nicking endonuclease signal amplification technology.A novel and sensitive biosensor based on the combination of nanoparticles and nicking endonuclease signal amplification technology was designed in this chapter.First,the probe single strand DNA and ruthenium complex were loaded at AuNPs,which was taken as an ECL?electrogenerated chemiluminescence?probe.Then,a great deal of solution contained DNA hybridized was gained by using cleavage of nicking endonuclease.When the capture ss-DNA with a thiol group was self-assembled onto the surface of gold electrode,and then hybridized with target ss-DNA and further hybridized with the ECL probe to form DNA sandwich conjugate,a strong ECL response was electrochemically generated.It provides a detection limit of 1.81×10-14M?3s?and the linear range from 3.0×10-14 to 6.0×10-12 M for thrombin determination.Chapter 3,Design of ultrasensitive chemiluminescence detection of lysozyme in cells based on nicking endonuclease signal amplification technology.This chapter desiged a biosensor based on the combination of MB?magnetic bead?,nanoparticles technology and nicking endonuclease signal amplification technology.Here a novel protein assay strategy was constructed by using cleavage of nicking endonuclease to allow for the sensitive and selective detection of lysozyme.In this strategy,detection signal is amplified through lysozyme-aptamer recognition and nicking endonuclease cleavage,by which one lysozyme produce many signal probes,nanoparticles chemiluminescence probes?ABEI-BSA@Au?.This nicking endonuclease signal amplification system provides a detection limit of 2.0×10-13 M?36?and the linear range from 1.0×10-12 to 1.0×10-11 M which also exhibits good selectivity for lysozyme detection.Sample assays of lysozyme in macrophage,K562 cells and B lymphoma cells confirm the reliability and practicality of the protocol,which reveal a good prospect of this platform for biological sample analysis.Chapter 4,Study on label-free biosensor for cancer cells using DNA encapsulated Ru?bpy?3Cl2 as signal probe.Two kinds of label-free sensing technologies?chemiluminescence and electrogenerated chemiluminescence?for the detection of cancer cell was developed.For electrogenerated chemiluminescence analysis,gold electrode as the sensing surface was firstly modified with long-strand DNA with five repeating units.Then two kinds of short-strand DNA are grafted onto the long-strand DNA.As the hybridization proceeds,the four kinds of DNA would finally transform into a three-dimensional network structure and the signal probe Ru?bpy?3Cl2 was encapsulated by DNA simultaneously.When cancer cells are introduced to interact with the aptamer,the signal probe is released.In order to confirm the generality of this method the ferrocenecarboxylic acid and luminol selected as a signal probe mode were also tested.Magnetic bead as the sensing surface was firstly modified with long-strand DNA with five repeating units and luminol selected as a signal probe mode.With this ECL biosensor,detection limit as low as 58 cells/mL and the linear range from 1.0×102 to 1.0×103 cells/mL were achieved for cancer cells.For CL?chemiluminescence?biosensor,detection limit as low as 126 cells/mL and the linear range from 2.O×102to1.0×103 cells/mL were achieved.Chapter 5,Study on the determination of cocaine based on nanoparticles chemiluminescence probe coupled aptamer.In this strategy,detection signal is amplified through lysozyme-aptamer recognition and nanoparticles,by which one cocaine produce many signal probes,nanoparticles chemiluminescence probes?ABEI-BSA@Au?.This method exhibits a good selectivity for cocaine detection and also provides a detection limit of 3.0×10-12 M?36?and the non-linear range from 1.0×10-11 to 3.0×10-7 M. |
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