Study On Electrochemical Determination Of Synthetic Colorant Sunset Yellow In Food Stuff

Food safety is a worldwide public health problem.It is not only closely related to human health,but also seriously affects the development of society and economy.One of the alarming problems in food field is that synthetic colorants are extensively used as food additives.Among various types of synthetic colorants,sunset yellow(SY)plays an important role in food industry and acquires consumers' acceptance,which can not only offer a yellow color for a long time but also improve the texture of foods.However,because of its azo functional groups and aromatic ring structures,SY can potentially induce serious side effects on human beings if excessively consumed.For the assurance of food safety and human health,convenient,rapid,reliable and economic methods for the on-site determination of SY in foodstuffs are extremely desirable.Various analytical methods have been applied to prevent the uncontrolled use of authorized colorants and their misapplication.Unfortunately,most of the detection methods require several time-consuming steps.Electrochemical approach has been considered to be a potent alternative for the determination of SY on account of their relatively short analysis time as well as high accuracy.Considering the excellent electrical conductivity and high specific surface area of carbon nanomaterials,this paper includes the following two parts:(1)A novel electrochemical platform was designed based on glassy carbon electrode modified by three-dimensional hierarchically porous graphitic carbon(3D HPGC/GCE).3D HPGC was synthesized using a conjugated polymeric molecular framework as precursor,the multivalent cross-linker and rigid conjugated framework help to promote graphitization during carbonization and chemical activation,which led to excellent electronic properties.Further,the synthetic materials were characterized,and the results shown that the materials have high specific surface area,large pore volume and hierarchical pore architecture.Under the optimized experimental conditions,the nanomaterial showed a highly electrochemical activity to SY compared with the performance of previously reported electrochemical sensors for SY.The constructed sensor expressed two linear relationships to SY concentrations from 0.3 nM to 30 nM and from 30 nM to 8.0 ?M with a low limit of detection(LOD)of 0.15 nM.The sensor also exhibited excellent selectivity for SY over its structural analogs,adequate reproducibility,ultrahigh sensitivity and good stability.Finally,the prepared sensor was used to detect SY in real spiked samples,and acceptable recovery(97%?102%)was obtained.The method has also been successfully applied to the simultaneous and rapid detection of SY and tartrazine.(2)A novel electrochemical platform was designed based on glassy carbon electrode modified by cuprous oxide coated copper nanospheres embedded the boron and nitrogen co-doped graphitic carbon(Cu@Cu2O-BNDC/GCE).The Cu@Cu2O-BNDC was prepared through a single step polymerization,followed by a carbonization.Further,the synthetic materials were characterized,and their electrochemical behavior towards SY was investigated.Under the optimized experimental conditions,the nanocomposite showed a highly electrochemical activity to SY compared with the performance of previously reported electrochemical sensors for SY.The improved behavior of the developed sensor can be attributed to the synergistic effect of Cu@Cu2O and BNDC.The constructed sensor expressed a linear relationship to SY concentrations from 10 nM to 8 ?M with a low LOD of 2.4 nM.The sensor also exhibited excellent selectivity for SY over its structural analogs,adequate reproducibility,ultrahigh sensitivity and good stability.Finally,the prepared sensor was used to detect SY in real spiked samples,and acceptable recovery(96%?103%)was obtained.Based on the experimental results,it is feasible to build a highly sensitive and anti-interference electrochemical sensor based on the advantages of carbon nanomaterials in amplifying the electrochemical signal and enhancing its stability,this provides a useful tool for the rapid detection of S Y in food.