Research On Optical Properties And Biological Detection Of MoS₂/Metal Composite Structure

With the aging of the population and the improvement of people's living standards,the incidence of diabetes in the population is gradually increasing.Therefore,measuring the blood glucose content has important research significance for the discovery and treatment of clinical diabetes.Surface-enhanced Raman spectroscopy(SERS)is an ultra-sensitive molecular detection technology that has the advantages of no pre-processing,high sensitivity,and single-molecule detection.It is widely used in the field of analytical sensing.The precious metal SERS substrate has excellent enhancement effect,but its adsorption capacity is weak and the background fluorescence is high,which will cause a certain interference to the Raman signal.As a typical graphene-like semiconductor material,molybdenum disulfide(MoS₂)has a certain adsorption capacity and fluorescence quenching effect,but its enhancement factor is not as good as that of a metal SERS substrate.In summary,combining the precious metal SERS substrate with MoS₂ to form a MoS₂/metal composite material as the SERS substrate,combining the chemical enhancement of MoS₂ with the electromagnetic field enhancement of metal nanoparticles can not only adsorb more detection molecules,but also generate plasmon resonance The effect enhances the Raman signal.The main research contents are as follows:(1)The MoS₂/Au nanoflower composite was prepared by a combination of hydrothermal method and thermal reduction method,and its structure,morphology,and Raman characteristics were characterized,and a SERS substrate was constructed to directly detect glucose.The results show that the characteristic peak intensity of glucose does not vary significantly with the concentration,the peak intensity is small and there are many noise interferences.Using MoS₂/Au/4-MPBA SERS substrate for indirect detection of glucose solutions of different concentrations,the detection limit is 10^-9 M;By testing multiple points on the same sample and checking the stability of the sample every three days,it proves that the substrate has good stability;Urea and vitamin C(VC)were selected as interfering substances for SERS specific detection,which proved that the substrate has good anti-interference ability.(2)A single-layer MoS₂ film was prepared by chemical vapor deposition,Au array was deposited on the MoS₂ film by electron beam lithography,and its morphology and Raman spectrum were characterized,and a MoS₂/Au nanoarray composite structure was constructed.The 4-MPBA was modified on the surface of the MoS₂/Au nanoarray,and the indirect detection of glucose was realized by 4-MPBA.The results show that the MoS₂/Au nanoarray composite structure has a good SERS enhancement effect on glucose molecules,and the detection limit is 10^-12 M.Multi-point testing on the same sample,stability testing of the sample every three days,and selection of urea and VC as interfering substances for SERS specific testing of the composite structure,proved that the substrate has good stability and resistance.Intrusive.