SERS Detection Of HCG And Hg(Ⅱ)by Peptides And Aptamer Regulating The Activity Of GO Nano-enzyme

Part Ⅰ IntroductionThe progress of surface enhanced Raman spectroscopy(SERS)technology,SERS enhancement mechanism,and the progress of SERS spectroscopy analysis and application,resonance Rayleigh scattering(RRS)spectroscopy and its analysis and application in environment were introduced.The research progress of nano enzyme,the types and preparation methods of main nano enzyme and nano enzyme catalysis technology were reviewed.The progress of nucleic acid analysis technology and its analysis and application in different fields were also briefly reviewed.The advances in the analysis of human chorionic gonadotropin and mercury ions were summarized.The main contents and significance of this research were briefly described.Part Ⅱ SERS detection of HCG by peptides and antibody regulating the activity of GO nano-enzymeIn water bath conditions,the reduction of HAuCl4 by trisodium citrate or H2O2 was slow,then the nano enzyme catalyst brought about a rapid reaction.With the increase of the amount of nano enzyme,the reaction was obviously enhanced.The concentration of synthetic gold nanoparticles in the system was increased,which shown a strong SERS effect with the VB4r molecule probe was added.The result of comparing catalytic activity of SERS experiments on several different nano enzyme shown that graphene oxide(GO)nano enzyme catalysis was the strongest,graphene oxide nanoribbons(GONR)and nano silica(SiO2)was second,the catalytic activity of GDot was weakest;HCG polypeptides and antibodies could combine with GO forming polypeptide/antibody-GO composite and reduced the contact area of the nano enzyme and reactant,so the catalytic activity was inhibited.The polypeptide on the catalytic activity of nano enzyme inhibition was better than antibody.In optimized experimental conditions,the HCG reacted with peptide or antibody,which reducing the concentration of free peptides and antibodies in the system,the GO nano enzyme concentration was not combined with the increased activation system catalytic effect.With the increase of HCG concentration,the rate of the system reaction increased and more gold nanoparticles were produced,and the SERS signal increased gradually.In the range of the 0.25-10 ng/mL concentration of HCG,the △I1613cm-1 value showed a good linear relationship with the concentration of HCG,the linear equation was △I1613cm-1=118.96C+19.51,the correlation coefficient was 0.9924.A new method of GO nano enzyme catalyzed SERS detection of HCG was established.Part III SERS and RRS detection of Hg2+ by aptamer regulating the activity of GO nano-enzymeMercury aptamer binding on GO surface had a good inhibitory effect on the catalytic activity of GO nano enzyme.Moreover,aptamers and Hg2+ could form a king of stable complexes,thus reducing the binding of aptamers to GO.Accordingly,a method for detecting Hgig by aptamer mediated GO nano enzyme catalytic activity spectrum was established.The experimental results showed that the △I1616cm-1 values of SERS increased linearly with the concentration of Hg2+ in the range of 0.25-10 nmoL/L,the linear equation was △I1616cm-1=264.07C+101.02,the correlation coefficient was 0.9849,and the detection limit was 0.08 nmoL/L;With the increased of Hg2+ concentration in the range of 0.5-10 nmoL/L,the reaction generated more gold nanoparticles,the intensity of resonance Rayleigh scattering spectra(RRS)scattering peak at 370nm added value showed a good linear relationship with the concentration of Hg2+,the linear equation was△I370nm= 162.9C + 111.71,the correlation coefficient was 0.983,and the detection limit was 0.17 nmoL/L.The method was applied for the analysis of Hg2+ in water samples with satisfactory,sensitivity,and rapidly.