Application Of Peptide/amino Acid Frameworks In The Detection Of Pesticide Residue

China is a large agricultural country,the use of pesticides is inevitable,all the time due to pesticide residues caused by the continuous occurrence of food safety incidents,has attracted the attention of the relevant departments,and pesticide contamination sensitive detection is one of the keys to ensure food safety.Due to the disadvantages of low sensitivity,complex operation and high cost,the traditional detection methods limit the rapid detection of pesticide residues.Therefore,it is necessary to establish an efficient and sensitive method to detect pesticide residues in food.Metal-peptide/amino acid frameworks(BioMOFs)are netlike nanomaterials composed of short peptides or amino acids interacting with metal ions through coordination bonds.Different peptide/amino acid and metal coordination results in different composition,network structure,pore size and shape of porous BioMOFs.BioMOFs is a kind of nanomaterial with high surface area and low density.Compared with previous nanomaterials,it has more binding sites,non-toxicity and better biocompatibility.And because the material is a new material,in all aspects of the application is less.Based on this,and based on the literature reports,a series of aptamer sensors based on metal-peptide/amino acid frameworks were developed to detect pesticide residues in food by using the excellent properties of metal-peptide/amino acid frame compounds.The details are as follows:(1)A peptide-based organic BioMOFs(GH-Cu BioMOFs)were synthesized from Gly-His(GH)dipeptide and Cu2+ as raw materials.It was found that GH-Cu BioMOFs exhibited fluorescence quenching and nucleic acid adsorption properties.Therefore,GH-Cu BioMOFs have been used to develop aptamer fluorescence biosensor methods for pesticide residue detection.Using acetamiprid as template analyte,due to the interaction between aptamer and acetamiprid,the fluorescence molecular-modified aptamer(FAM-DNA)adsorbed on the surface of GH-Cu BioMOFs was far away from the surface of nanomaterials,so the BioMOFs could not quench fluorescence and recover fluorescence.The method showed a good linear relationship in the range of 0-3 μM for the detection of acetamiprid,and the detection limit was 137 nM.Finally,the determination of acetamiprid pesticide in rice samples showed that this method has a strong potential in food safety detection.(2)A novel BioMOFs(Ser-Cu BioMOFs)were synthesized using Serine(Ser)as an organic ligand and Cu2+as metal ions.Studies have found that it also has the ability to adsorb nucleic acid and quench fluorescence properties.Due to these properties,a novel nano-aptamer sensor based on Ser-Cu BioMOFs nanomaterials and fluorescence aptamers was constructed for the detection of pesticide residues in Chinese cabbage.The method showed a good linear relationship in the range of 0-0.8μg/mL for thiophosamine,and the detection limit was 82 ng/mL.The above conclusions indicate that the method has a strong practicability in food safety detection.