The Preparation Of Nanomaterials/Amino Acid Chemically Modified Electrodes And Their Applications In Synthetic Food Dyes Analysis

Edible synthetic pigment is an indispensable part of food production.The bright color can improve the quality of food,stimulate people’s appetite and purchase desire.Synthetic pigments are mostly made from benzene compounds by organic or inorganic reactions.It is toxic and harmful to children and even induces cancer.Therefore,it is very important to establish a highly efficient and simple method for the detection of edible synthetic pigments.Chemically modified electrode,which has the advantages of simplicity high sensitivity,good stability and good reproducibility,has been widely used in the detection of synthetic pigments.In this study,PVAL-MWCNT/GEC,PLA-MWCNT/GEC and PVAL-GO/GCE modified electrodes were prepared and used in the determination of the edible synthetic amaranth,sunset yellow and allura red.1.The PVAL-MWCNT/GEC was prepared.The surface morphology of the modified electrode was characterized by scanning electron microscopy（SEM）.The electrochemical response behaviors of amaranth under the best experimental conditions were studied.The results indicated that compared with the glassy carbon electrode（GCE）,the oxidation peak current of amaranth was better,current value was higher.The modified electrode of amaranth has a good electrocatalytic activity.Under the condition of Na₂HPO₄-C₆H₈O₇ buffer solution（pH=2.2）,in the range of 2.5×10^-7-1×10^-33 mol·L^-1（R²=0.9911）,the lowest detection limit（S/N=3）was 8.3×10^-8mol·L^-1.The modified electrode can be used to detect amaranth in a simple,efficient and accurate way.2.The PLA-MWCNT/GEC was prepared.The surface morphology of the modified electrode was characterized by scanning electron microscopy（SEM）.The polymerization conditions of the modified electrode and determination on sunset yellow of the selection of the solution,pH,the static time and the scanning speed were optimized.The results indicated that compared with the glassy carbon electrode（GCE）,the oxidation peakand reduction peak of sunset yellow were better,the peak current value is much higher.The PLA-MWCNT/GEC has good selectivity.By differential pulse voltammetry to measure the linear range of sunset yellow at the modified electrode was 5×10^-7-1×10^-33 mol·L^-1（R²=0.9896）,the lowest detection limit（S/N=3）was 1.67×10^-7mol·L^-1.The modified electrode can be used to detect the sunset yellow quickly,efficiently and accurately.3.The PVAL-GO/GCE was prepared.The surface morphology of the modified electrode was characterized by scanning electron microscopy（SEM）.The electrochemical behaviors of allura red were studied under the optimal experimental conditions.The experimental results were as follows.Compared with the glassy carbon electrode（GCE）,the oxidation and reduction peak of the allura red were better,the peak current value is much higher.Electrocatalytic effect of The modified electrode allura red was better.Under the condition of Na₂HPO₄-C₆H₈O₇ buffer solution（pH=3.4）,in the range of 7.5×10^-7-1×10^-44 mol·L^-1（R²=0.9964）,the lowest detection limit（S/N=3）was 2.5×10^-7mol·L^-1L with DPV.The modified electrode can be used to detect the allura red quickly and efficiently and accurately.