Nanozyme Catalytic Reaction-surface Enhanced Raman Scattering Spectral Method For The Detection Of Glucose,Clenbuterol And Adenosine Triphosphate

Since the discovery of Fe₃O₄ magnetic nanoparticles as peroxidase in 2007,nanozymes have developed rapidly as a new class of peroxidase.Their excellent catalytic activity and biocompatibility have attracted the attention of researchers,but many of their catalytic properties need to be further developed.Surface-enhanced Raman scattering?SERS?is a simple and sensitive method for molecular spectroscopic analysis,and the molecular structure information can also be provided.The combination of SERS and nanozyme catalysis can further improve the sensitivity of the method.In this paper,we plan to prepare a series of nanozymes,and construct the nanozyme catalytic systems,and study the catalytic laws.Then the nanozymes were modified,and the mechanisms of catalytic enhancement were discussed.Then,the nanozyme catalysis is combined with the selective biological enzyme catalytic reaction,the immune reaction and the aptamer reaction to regulate the catalytic activity of the nanozyme,and a simple,sensitive and selective nanozyme catalytic-SERS platform is constructed.Under the light wave irradiation,the salmon silver nanosol?AgNP?with good stability and high SERS activity is prepared by reduction of AgNO₃,using sodium citrate as the reducing agent.In pH 7.0 Na₂HPO₄-NaH₂PO₄ buffer solution?PBS?,glucose oxidase can catalyze glucose to produce H₂O₂ specifically.In the presence of nanocatalyst and SERS substrate of AgNP,the 3,3',5,5'-tetramethylbenzidine?TMB?can be oxidized by H₂O₂ to produce blue oxidation product(TMB_ox)that cause the AgNPs aggregation,which show a strong SERS peak at 1606 cm^-1.The SERS signal has a linear relationship with the glucose concentration.Based on this,a new SERS quantitative analysis method for glucose detection was established based on glucose oxidase coupled with nanosilver catalysis.The SEM and infrared spectra were used to verify the generation of TMB_ox.The absorption spectra proved that the AgNP can be aggregated by TMB_ox.Comparing the sensitivity of different SERS probes and nanosilver with different shapes to detect glucose,the TMB-AgNP system was found to be the most sensitive.Finally,this system was applied to the detection of glucose in serum with good results.The high catalytic activity carbon dots?CD?doped with N,S,Ag,N/S,N/Au and N/Ag are prepared by hydrothermal method using fructose as the precursor,and their catalysis for the reaction of trisodium citrate-HAuCl₄ are studied.The results show that CD can strongly catalyze the reaction of trisodium citrate-HAuCl₄ to form red gold nanoparticles.In the presence of Victoria Blue B?VBB?,the system exhibits strong Raman signal,in which the catalysis of CD_N/Ag is the strongest.Combining carbon dots catalytic reactions with immune reactions,a simple and sensitive immunological regulation of CD_N/Ag activity SERS method is established to detect clenbuterol?Clen?.TEM,SEM,energy spectrum,particle size analysis and potential analysis were used to characterize the carbon dots and the systems.The catalytic laws of carbon dots doped with different elements and different doping ratios were studied,and then the possible catalytic enhancement mechanism of carbon dots after doping different elements was deduced.Finally,the method is applied to the detection of Clen in food.Based on aptamer-mediated covalent organic frameworks?COFs?nanocatalytic amplification signal strategy,a novel surface-enhanced Raman scattering/resonance Rayleigh scattering?SERS/RRS?coupled dual-mode analysis method is developed for the detection of adenosine triphosphate?ATP?.COF was prepared by solvothermal synthesis method,based on the rich amino groups on the surface of COF,Au element was introduced into the surface of COF to prepare the Au-doped COF?AuCOF?,and its catalytic performance for AgNO₃-trisodium citrate?TC?-citric acid?CA?reaction is investigated.The combination of AuCOF catalytic reaction and aptamer reaction greatly improves the selectivity of the system.Because the catalytic products have strong SERS and RRS effects,and their intensity are proportional to the concentration of nanoparticles,the SERS/RRS dual-mode analysis method can be established by coupling RRS with SERS,which greatly improves the sensitivity of the system.TEM,XRD,energy spectra and infrared spectroscopy were used to characterize the COF materials.From their results,the structure of the COF materials can be clearly seen,which also proves the successful doping of Au/Ag.The catalytic laws of COFs before and after doping were studied,and the mechanism of catalytic enhancement after doping with Au/Ag was also studied.Finally,this method is applied to the detection of ATP in drugs,and the effect is better.In this paper,metal nanoparticles,carbon dots and COFs are used as nanozymes,through the establishment of nanozyme catalysis coupled with the biological enzyme-catalyzed reaction,and immune/aptamer-adjusted nanozyme-catalyzed reaction,which provides a reference for improving the selectivity and sensitivity of analytical methods.The discussion on the change law of the catalytic activity of the nanozyme before and after doping provides data support for the study of the catalytic mechanism of the nanozyme,which has certain practical significance.The establishment of nanozyme catalyzed-SERS analysis platform expands the scope of application for the detection of trace organic small molecules.