Research On Fast Detection Of Animal Derived Food Safety Based On Graphene And Single-atom Iron Two-dimensional Materials

In recent years,the quality problems of animal derived food have occurredfrequently,which has seriously endangered public health and safety.The simple,fast and sensitive detection and identification technology developed based on the excellent physical and chemical properties of two-dimensional nanomaterials has great significance for controlling the quality of animal derived food.This paper mainly focused on two-dimensional graphene and two-dimensional single atom Fe catalyst.The solution-gated graphene transistors?SGGT?using two-dimensional graphene as the channel were established to realize rapid determination of freeze-thaw meat,and colorimetric sensor platform using two-dimensional single-atom Fe catalysts?SA-Fe/NG?as a peroxidase for rapid detection of Cr???in aquatic products.The specific research contents were as follows:1. Research on the mechanism of detecting hemin based on solution-gated graphene transistors.A hemin electrochemical sensor piatform based on solution-gated graphene transistors was constructed and prepared,and its performance was further characterized.The?-?interaction between hemin and two-dimensional single-layer graphene and the n-type doping effect of hemin on graphene were studied.2. Rapid identification of freeze-thaw beef based on solution-gated graphene transistors.We took the loss of hemin in beef exudates as an important basis to judge freeze-thaw quality of beef.The rapid detection of hemin was successfully achieved by SGGT.The detection mechanism was based on the n-type doping effect of hemin on the graphene channel.The sensor has extremely high sensitivity to hemin,the detection limit is as low as 10 n M,and the linear detection range is 100 n M to 10?M.The hemin sensor based on SGGT has good selectivity for some interfering components such as proteins,amino acids,and cations in beef exudates as well as certain hemin analogs.And it has been successfully applied to the rapid determination of freeze-thaw quality in actual beef samples.3. Preparation and characterization of two-dimensional single-atom Fe materials.We used g-C₃N₄and iron source as precursors to successfully anchor monoatomic iron to two-dimensional nitrogen-doped graphite carbon through high temperature pyrolysis to prepare two-dimensional single-atom Fe catalysts?labeled SA-Fe/NG?.The electron microscopy morphology,elemental composition,content,valence state,structure of related compounds were characterized,and the peroxidase activity was determined.The results showed that SA-Fe/NG had ideal two-dimensional nanostructure and extremely high catalytic activity due to its 100%atomic utilization and existing Fe-N-C structure.4. Colorimetric method based on two-dimensional single-atom Fe catalyst as peroxidase mimic for rapid detection of Cr???in aquatic products.We used SA-Fe/NG as a efficient peroxidase mimic,8-hydroxyquinoline?8-HQ?as an inhibitor,which can prevent the oxidation of TMB.The interaction between Cr???and 8-HQ resulted in color recovery as the detection mechanism.The colorimetric conditions were further optimized.The colorimetric sensor has extremely high sensitivity,the detection limit is 3 n M,and the linear range is 30 n M to 1?M.It has high selectivity for a series of metal cations and successfully applied to the rapid detection of Cr???in tuna samples.