Research On Rapid Detection Method Of Ractopamine Based On Enzyme-linked Nano-gold Composite Probe

Food poisoning incidents have occurred more and more frequently in our years.At present,ensuring the quality and safety of food is becoming more and more urgent.It has become a major concern of the media and the public in the world.In the late 1980s,there were constant“clenbuterol”incidents in the world that caused panic among the people of the world.The direct cause of this incident was the“clenbuterol”left in animal foods,and acute poisoning occurred after eating.Symptoms,therefore,we need a quick test of“Clenbuterol”for all kinds of meat products in our daily life.In this paper,a novel enzyme-linked nano-gold composite probe was constructed and further developed and extended in the field of immune technology,so that it can be better applied in the detection of the second generation of clenbuterol ractopamine.This method is to mark the antibody with biotin and then combine it at the surface of the gold nanoparticles.Streptavidin-biotin can specifically recognize horseradish peroxidase?HRP?,so HRP can be combined with the gold nanoparticles to synthase the gold nanoparticles composite probe.Using this method,a single gold nanocomposite probe carries about 15 HRP molecules.Combined with magnetic bead technology,the nanogold composite probe can be used to detect ractopamine.Ractopamine as a target,through the specific recognition of antigen-antibody,magnetic beads,nano-gold composite probe can form a"sandwich"immune complex,horseradish peroxidase catalyzes the substrate to cause color change Thereby an optical signal is emitted.After comparison with the traditional enzyme-linked immunosorbent assay?ELISA?,the sensitivity of the immunoassay of this novel composite probe was increased by 10 times,and the detection limit was1.42 ng·L^-1,which not only had High sensitivity and good specificity.Beef,pork and mutton samples were subjected to ractopamine addition recovery experiments using enzyme-labeled nanogold probe method and ELISA method at three concentrations of 1 ng·g^-1,5 ng·g^-1 and 10 ng·g^-1.Under the addition level,an additive recovery rate was obtained between 78.5% and 93.4%,and the RSD ranged from 11.6% to 19.3%.This result indicates that the method has better precision and higher accuracy.After comparison with the traditional ELISA method,it can be found that the linear relationship between the enzyme-labeled nanogold probe method and the traditional ELISA is better.The reliability of the immunoassay method based on the enzyme-labeled nanogold composite probe was confirmed.