Development Of Highly Sensitive Surface Enhanced Raman Substrates

Since the discovery of surface enhanced Raman scattering(SERS),SERS spectroscopy has been widely used in biology,medicine,chemical analysis and other fields because of its advantages,such as high-sensitivity,rapidity,high-efficiency,simpleness.Especially when the target molecules is lower than ppb level,the advantage of SERS spectroscopy is particularly prominent,it can be used to detect the characteristic Raman spectra of biochemical samples in a complex system,and can be used to detect,identify and even calibrate the content.China's food safety problems have occurred in recent years,simple and efficient SERS spectroscopy plays an important role in food safety testing.The key to the application of SERS in food safety testing is to prepare the SERS substrates with economy,better enhanced effect and high reproducibility.In this paper,the FDTD method is used to theoretical calculate the scattering spectra and spatial electric field distribution of pyramid,truncated pyramid,ellipsoid,box,mi,lattice.The surface plasmon resonance characteristics of the substrate are analyzed,and the respective SERS effects are studied.The simulation results show that the micro-morphology of the substrate surface will produce better enhancement effect,and the effect of complex morphology is better than the single morphology.While the size of shape changes,the law of the scattering spectra will change.In the experiment,electron beam exposure and soft template embossing technology were used to prepare the gold substrate with meter shape and lattice morphology,and used for the measurement of the Raman scattering spectra of cystine and melamine.The results show that the Raman characteristic peaks of cystine at a concentration of 50 ppm can be detected on the meter shape gold substrate and the lattice gold substrate,and the Raman signature of melamine at a concentration of 50 ppm can also be detected on the meter shape gold substrate.