Study On Electrochemical Immunosensor Based On The Novel Mimic Peptide Of Zearalenone

Zearalenone(ZEN)poses a threat to human health through enrichment in the food chain,so the monitoring of this substance at home and abroad has attracted much attention.In recent years,with the rapid development of computer simulation and sensing technology,this study combines the two technologies to provide a new idea for the rapid detection of ZEN.The simulation algorithm performs high-throughput screening of peptide sequences,which saves a lot of time.Electrochemical immunosensors have strong specificity,high sensitivity and easy operation,which provides a new idea for food safety detection.The mimic peptide retains the action site to the greatest extent,and has a small molecular weight and is easy to prepare.In this study,the specific peptide sequence library of ZEN was constructed by molecular docking,molecular dynamics,amino acid mutation and other technologies;four polypeptide chains(L0,L1,L2,L3)were screened according to the principle of energy scoring.At the same time,electrochemical AC impedance method verified the binding ability of specific peptides to ZEN.The results showed that the binding ability was L2>L1>L0>L3,which was consistent with the interaction energy scoring trend in molecular simulation,so the mimic peptide L2 was determined.As an identification element for electrochemical sensors.Construction of a ZEN immunosensor based on Au NPs/r GO-COOH-Atp composite mimic peptid.In the experiment,the addition ratio of GO-COOH to Atp,the concentration of polypeptide chain L2 and the incubation time were optimized.When the concentration range was from 0.01 ng/m L to 10 ng/m L,the DPV response difference was linearly related to-lg C,with an R~2 of 0.9964 and a detection limit(S/N=3)of 0.91 pg/m L.The constructed electrochemical immunosensor has good specificity,reproducibility(RSD=1.94%)and stability.Through the spike recovery experiment of food samples,such as corn.The recovery rate ranged from 84%to 105.3%.At the same time,the comparison experiment of commercial ELISA kits proved that the constructed sensor has good practicability.In addition,Au NPs/r GO-COOH-Atp composites modified screen-printed carbon electrodes to construct a peptide-mimicking ZEN immunosensor to achieve sensor miniaturization and portability.Under the optimal conditions,the linear range of the method was 0.01ng/m L～0.2 ng/m L(R~2=0.9928),and the detection limit(S/N=3)was 1.997 pg/m L.The method has good specificity and reproducibility.The comparison experiment of the actual sample spike recovery and commercial ELISA kit proves that the screen-printed immunosensor can be used for the detection of actual samples.Construction of novel immunosensors based on Au NPs@f-CNFs sensitized materials.The screen-printed carbon electrode is modified by electropolymerization,which improves the detection sensitivity and material stability.In this study,the materials were characterized by TEM and XRD,and the relevant conditions affecting the sensitivity of the sensor were optimized.In the range of 0.02 ng/m L～12 ng/m L,the current response value of the immunosensor showed a good linear relationship with lg C,the correlation coefficient R~2 was 0.9912,and the detection limit was 0.79 pg/m L.In addition,the use of this immunosensor to detect ZEN in corn,oat and other samples.It shows that the recovery results of standard addition are 84.0%～101.6%,indicating that the sensor has good detection performance in the rapid detection of actual samples.At the same time,it has good specificity,reproducibility and stability.