Specific SERS Detection Based On Molecular Impringing And Immunology

Surface enhanced Raman scattering(SERS)refers to phenomenon that the enhanced local electric field significantly increases the the probability of Raman scattering and Raman signal intensity of the molecules adsorbed on or near the metal surface when incident light irradiates the surface of noble metal nanoparticles(Au NPs or Ag NPs).The SERS detection technology developed based on this phenomenon has been widely concerned in the detection fields of food safety,biomedicine and environmental pollution due to its fast,nondestructive and sensitive characteristics.However,a real system is quite complicated,containing many interfering species.The sensitivity of the SERS method is drastically reduced when analytes are at a low concentration level or incapable of remaining in the “hot spot”(an area that produces a localized enhanced electromagnetic field)by its own chemisorption or physisorption.due to Raman spectroscopy lacks selectivity for specific molecules.To solve this problem,in this work,two kinds of novel SERS methods and corresponding SERS detection substrates based on molecular imprinting technology and immunology specific binding principles are developed.Detailed information is described as follows:(1)A porous molecularly imprinted polymer(pMIP)was combined with self-assembled Au NP array(AuA)to fabricate a novel surface enhanced Raman scattering substrate(AuA-pMIP).The thickness of molecularly imprinted polymer during preparation was optimized.As an example,the sensor prepared under optimal conditions was used to measure R6 G.The results demonstrated the AuA-pMIP can realize the quantitative detection of R6 G in aqueous solution with wide linear range and lower detection limit.It was verified that AuA-pMIP can achieve specific detection of R6 G under the interference of rhodamine B(RB),Rhodamine 123(R123)and crystal violet(CV),and shows high reproducibility.The detection of real orange juice samples shows that the AuA-pMIP substrate also exhibits excellent specific detection and quantitative ability in practical applications.(2)The antigen-antibody immunology was combined with surface-enhanced Raman method to establish a SERS detection method for disease marker human immunoglobulin IgG.The preparation process of SERS tag and SERS substrate was optimized.Based on the antibody-antigen-antibody sandwich structure,the novel method can achieves quantitative detection of IgG with a wide linear range and lower detection limit.It was verified that the method can achieve specific detection of R6 G under the interference of human hemoglobin(Hgb)and human serum protein(HSA)and the SERS substrate shows good uniformity.