Research On LSPR Biochemical Sensor Chip Based On Interference Exposure Technology

Localized Surface Plasmon Resonance(LSPR)is a phenomenon that free electrons are resonating in noble metals due to the excitation of light waves.When the incident light is irradiated onto the metal surface,the frequency of the light wave is the same as the electronic frequency of the metal nanostructures,which will cause the surface charge of metal to oscillate.At this time,the electromagnetic field on the surface of metal nanostructures will be greatly enhanced,which promotes the metal nanostructures sensitively to the change of refractive index near the surface.If the biomolecules to be detected are modified on the surface of metal nanostructures,it will be possible to achieve sensing detection about the analyte by measuring the change of the spectrum.In order to prepare the nano-graphic structure,a Lloyd interference exposure system is built to have successfully fabricated nanometer grating,lattice and hole arrays on 2x2cm2 ITO glasses and silicon substrates.Then through the electron beam evaporation and lift-off process,the metal nanostructures with excellent sensing properties were fabricated,which will provide the prerequisite for the preparation of the sensing chips.The prepared metal nanostructures are simulated by FDTD Solutions software to analyze the influence of the shape,size and material on the sensing properties.The spectral characteristics of gold nano-lattice arrays with different sizes under different refractive index sensitivity are simulated.The results show that the red-shift of the wavelengths obviously occurs with the increase of the refraction index.The work provides a reference for the post-chip sensor testing.Finally,the prepared metal nanostructures have been tested.From the test results,it has verified the influence of the parameters of Au nanoparticles on the refractive index sensitivity.The results of this study shows that the sensitivity of the gold nano-lattice sensor chip could reach 533nm/RIU.The work of this paper provides a reference for the research of high sensitivity LSPR sensor,which has a high application value in biochemical sensing field.