Construction Of Cytosensor And Molecular Sensing Platform Based On Electro-Chemiluminescence Of Semiconductors

Electrochemiluminescence(ECL)is an analytical technique combining electrochemical methods with chemiluminescence methods which is used as the main detection technique in this work.By preparing of semiconductor nano array composite electrode and nanomaterialsmodified electrode as chemiluminescence material,the sensitive ECL cyto sensor and ECL molecular detection platform were constructed in this study.In the first chapter,the basic principle,characteristics,main reaction types,applications and development prospect of ECL in biological analysis sensors are briefly reviewed.Then,the semiconductor nanomaterials and graphite like materials g-C3N4 are briefly introduced.In the end,the significance of the study and research content of this thesis are summarized.In the second chapter,a highly sensitive ECL sensor based on CdS/ZnO nanocomposite array is proposed.Telomerase,as a tumor marker,plays an important role in early diagnosis.The aligned ZnO nanorods are grown on titanium substrate by a hydrothermal method,and then CdS nanoparticles are assembled on the ZnO surface by a layer-by-layer assembly technique to form composite electrodes.Afterwards,(TTAGGG)n as the production of telomeric extension reaction is combined with the complementary strand modified on carbon nano spheres to realize the quenching of the ECL signal.The value of ?I/I0 and telomerase concentration shows linear and exponential linear relationship respectively.The available detection range is 2?10 cells and 10?8×104 cells respectively.The detection limit reaches the single cell level.In the third chapter,a modified electrode based on graphite like g-C3N4 and Ag nanoparticles is developed H2O2 and glucose sensing.The 2D g-C3N4 nanosheets are prepared by microwave digestion technique,and silver nanoparticles are in-situ generated on nanosheets.H2O2 molecules react with silver nanoparticles to achieve the recovery of the ECL signals from weak to strong.Our results demonstrate that the value of ?I is proportional to the concentration of H2O2 and glucose in the range from 5?200 ?M and 0.1?40 ?M respectively.The lowest detection limits for H2O2 is 0.4?M and for glucose is 0.05 ?M.