Three Kinds Of Surface Plasmon Coupling Electrochemiluminescence Sensing System For Bioassay Application

Electrochemiluminescence(ECL)refers to a light emission process under the control of electrochemical reaction,which has become a powerful analytical method with high sensitivity,low background,fast response and wide dynamic range.The surface plasmon coupling effect between noble metal nanomaterials and ECL luminophores can enhance the emission signal and control the direction of ECL radiation,providing higher sensitivity and resolution.The regular and orderly plasmonic patterned structures have the advantages of high-density and uniform electromagnetic hot spots,providing efficient substrates for sensing research and applications.Therefore,the different patterned structures were constructed as ECL sensing platforms in this work.We have investigated the construction strategy of patterned structures.Based on the surface plasmon coupling effect,the changes of ECL intensity and polarization characteristics have been studied deeply.Furthermore,we have detected cancer-related nucleic acid markers in tumor samples and explored the potential value of the sensing method in practical clinical analysis.This work is listed as the following five parts:In the first chapter,we introduced the basic ECL mechanism and biosensing applications.Then,the principle and the recent research results of surface plasmon coupling effect were elaborated.We have discussed the regulation of patterned structures on electromagnetic hot spots and their applications in surface enhanced research.Finally,the significance and content of the research were described.In the second chapter,phenylboronic acid regulated chitosan nanoemitters were prepared with microwave assisted hydrothermal method.The flower-like silver nanostructures were in situ grown on the electrode surface by electrochemical deposition as the structural units.The flower-like silver nanostructures with multi-layer branching structures produced surface plasmon coupling effect,which effectively increased ECL intensity.The concentration of mutant KRAS gene was successfully detected in colorectal cancer tissue samples.In the third chapter,the solvent evaporation induced self-assembly method was used to construct the Au nanobipyramids patterned structures with different orientations.We investigated the effect of the arrangement mode on surface plasmon coupling and hot spots distribution.The vertical Au nanobipyramids significantly promoted the ECL intensity and polarization characteristics.Based on the vertical Au nanobipyramids patterned structures,we constructed the polarization-resolved ECL sensing system and analyzed the abnormal expression of mi RNA-21 and mi RNA-205 in triple negative breast cancer tissue samples.In the fourth chapter,Ag nanowires and Au nanostars were employed as structural units for constructing three-dimensional plasmonic nanostructure.It provided uniform and high-density electromagnetic hot spots in three-dimensional space.Au nanostars changed the isotropic ECL into polarized emission.Ag nanowires guided the directional propagation of light to improve polarized resolution.The three-dimensional plasmonic nanostructure-based polarized ECL biosensor was used to analyze the expression level of exosomal mi RNA-146b-5p in the thyroid tumor microenvironment.The fifth chapter summarized the research work and brought up future research expectation.