Two-dimensional Encoded Surface-enhanced Raman Scattering (SERS)Emissions On Single Particle

Surface-enhanced Raman Scattering(SERS)has advantages such as high sensitivity,high light stability,suitable for multi-objective analysis and so on,which has won the favor of research scholars.SERS has developed into a powerful analytical method in the fields of biochemistry and life medicine.In recent years,SERS tags containing SERS substrates and Raman signal molecules have developed rapidly.Compared to other optical tags,due to the combination of the ultra narrow band of the SERS signal and its simultaneous encoding in the two dimensions of peak position and peak intensity,SERS tags produce massive,uniquely identified and stable optical signals,demonstrating tremendous potential for high-throughput detection and analysis.Therefore,the one-dimensional and two-dimensional combination of SERS signals on single particles to construct a new SERS tag is an important issue.By designing and preparing the core-shell and dimer nanostructures,the triple-bond signal molecules are quantitatively modified and encapsulated on single particle to realize the twodimensional encoding of the SERS signal.The specific research contents are as follows:1.The Au@Ag nanostructure was used as the SERS substrate,two kinds of triplebond signal molecules located in the Raman quiet region were anchored between the gold and silver layers to amplify the characteristic signals while preventing the signal molecules from being interfered by the environmental system.Combining the triplebond signal molecules,SERS and coding technology,the two-dimensional coding of the SERS signal in the Raman quiet region was designed,which avoids the interference of biomolecules signal in the fingerprint area.It realized the output of multiple signal codes using a finite number of signal molecules,and gave the application ideas of twodimensional coding in multi-component and high-throughput detection,which provides a practical method for designing more coded tags.2.Due to ?-cyclodextrin can undergo host-guest reaction,and it can be used as reducing agent and stabilizer,a kind of dimer nanoparticle with hot spot structure was designed by using ?-cyclodextrin at the first time.The Raman signal molecules were protected in the hot spot,its signal stability and SERS enhancement effect are greatly improved,which provides a new means for the construction of dimer SERS tags.By quantitatively modifying different signal molecules,three two-dimensional coded SERS signal outputs were designed with good reproducibility and simulated as barcodes and colors.The three encoded SERS tags were modified by bacterial aptamers and applied to micron-sized bacteria to achieve the purpose of distinguishing different coded signals under the same experimental conditions,and the application of coding SERS tags was expanded.