Surface Enhanced Raman Technology Derived Sensor For Melamine Detection

Melamine?Melamine,C₃N₃?NH₂?₃?is a triazine nitrogen-containing heterocyclic organic compound.Due to its high nitrogen content?66.6%?,it is often illegally added to milk and various dairy products.Melamine is difficult to metabolize,and excessive consumption of animals or people can produce varying degrees of renal failure,serious and even lead to death.Therefore,it is necessary to study simple,fast,low-cost,convenient and high-sensitivity methods to detect melamine.In this paper,a rapid label-free melamine detection sensor is designed to detect melamine with high sensitivity.The main research contents include:1?Electromagnetic enhancement calculation on the surface of silver nanoparticles.To clearly illustrate the local electromagnetic field enhancement effect on the surface of silver nanoparticles,commercial COMSOL Multiphysics RF modules were used to simulate the local surface electromagnetic enhancement effect of silver nanoparticles.We found that there is a phenomenon of localized electromagnetic field enhancement on the surface of silver nanoparticles,which is about 83,000 times greater.2?Research on the preparation of Ag/PPy composite SERS substrate by self-assembly method.The method of preparing homogeneous Ag nanostructures on modified polypyrrole?polypyrrole,PPy?membranes by direct chemical deposition has achieved the high sensitivity and repeatability detection of the target analyte melamine directly on a Ag/PPy nanostructured substrate.The Raman characteristic peaks of melamine were obtained by experiments and the SERS detection conditions of melamine on the substrate were optimized.SERS substrates based on uniform dense silver nanostructures have higher sensitivity and lower cost synthesis,providing a new strategy for their applications in chemical and biomolecular sensing and food safety.3?Melamine sensors based on in situ electrochemical detection of SERS substrates were constructed based on modified polypyrrole?PPy?and silver nanoparticles?Ag NPs?.Uniform and dense silver nanostructures can significantly enhance the Raman signal of melamine molecules,up to 440 times.We believe that this preparation of uniform silver nanostructures on PPy films provides a convenient and sensitive method for the detection of melamine on the films,which may open new avenues for the preparation of highly sensitive and reproducible SERS active substrates for the detection of chemical and biomolecules.