Chemiluminescence Optical Fiber Immunosensor Based On Magnetic MOFs Materials For The Detection Of Deoxynivalenol

Grains such as wheat,corn,and rice are the source of carbohydrates for billions of people around the world,and are easily contaminated by deoxynivalenol（DON）during production,storage and transportation.Therefore,the development of an effective DON detection method is of great significance for ensuring food safety.However,most of the developed detection methods require cumbersome pre-processing,expensive instruments and professional operation skills,making it difficult to be used widely in on-site rapid detection.Based on this,this topic designed a new type of magnetic metal-organic framework（Fe₃O₄@MOF-5）material to specifically extract and enrich DON in grains.Besides,two chemiluminescent optical fiber immunosensors for the detection of DON were constructed,and their application in high-sensitivity detection of DON in grains.The novel immunosensors constructed in this subject provides a new idea for the field detection of mycotoxins represented by DON in grains.The specific research contents are as follows:1.Study on enrichment of DON in grains based on Fe₃O₄@MOF-5In order to solve the problems of long extraction time,poor stability,high cost,and the unreliable extraction column in the process of sample pretreatment,high-temperature hydrothermal synthesis method was used in this chapter to successfully prepare Fe₃O₄magnetic nanoparticles with good dispersion,uniform particle size and superparamagnetic properties.On this basis,square Fe₃O₄@MOF-5 were successfully synthesized by the coordination of central metal ion Zn²⁺with terephthalic acid.In addition,the adsorption behavior of DON on Fe₃O₄@MOF-5 was explored by kinetic experiments of Langmuir model and Freundlich model.Finally,using DON as a template molecule,the efficient enrichment and extraction of DON in grains was achieved by exploring its optimal conditions and adsorption process for DON extraction.The experimental results show that Fe₃O₄@MOF-5 has a maximum adsorption capacity of 1.68 mg/g for DON,and the rapid enrichment of DON in grain samples can be achieved within 10 min.Compared with the traditional pretreatment method,the constructed Fe₃O₄@MOF-5 material has the advantages of low cost and low pollution,and has potential industrial application value and good market prospect in the direction of sample pretreatment.2.Chemiluminescence-based optical fiber immunosensor for the detection of DONIn order to meet the needs of rapid on-site detection of mycotoxins,it is of great significance to construct a biosensor with simple operation,high sensitivity and good stability on the basis of developing a new sample pretreatment platform.In this chapter,a chemiluminescent optical fiber immunosensor was constructed based on chemiluminescence and fully antigen-functionalized fiber optic probes.The optical fiber probe in the sensor simultaneously serves as a solid-phase carrier and a signal transduction element for biological recognition molecules,which greatly reduces the complexity of the instrument.The results showed that the constructed fiber optic immunosensor exhibited a good linear relationship between 0.1-1000 ng/m L,and the detection limit was 64.3 pg/m L.In addition,the developed chemiluminescent fiber optic immunosensor was also applied to the detection of DON in wheat samples,with recoveries in the range of 79.0%-91.0%and relative standard deviations less than 13.46%.The chemiluminescence optical fiber immunosensor constructed in this chapter is small in size,strong in anti-interference ability,high in sensitivity and good in stability,which provides a new idea for the rapid detection of mycotoxins in grains.3.Homogeneous chemiluminescence-based optical fiber immunosensor for the detection of DONMost chemiluminescent biosensors require multiple washing steps in the detection process,which greatly limits their application in the field of rapid detection.In this chapter,on the basis of the original chemiluminescence optical fiber immunosensor,an immunosensor based on homogeneous chemiluminescence was constructed with the fiber probe as the solid carrier.By immobilizing the antibody and the luminescent substrate on the surface of the optical fiber,the conversion of the immune signal to the chemiluminescent signal is realized in the microenvironment of the optical fiber surface through the competitive reaction,so as to improve the accuracy and stability of the detection.The results show that the constructed homogeneous chemiluminescence fiber optic immunosensor has a good linear relationship for DON in the range of 0.1-500 ng/m L,and the lowest detection limit is 74.6 pg/m L.In specific experiments,it was verified that the proposed sensor was not interfered by food matrices and mycotoxins,and the recoveries in rice spiked samples ranged from 81.0%to 118.2%,and the relative standard deviation was lower than 14.12%,which could be used in real samples stable detection of DON.The sensor has the advantages of simple operation,light weight and portability,and low detection cost.