Nucleic Acid Aptamers Are Used In The Colorimetric Detection Of Antibiotic Residues In Dairy Products

The discovery of antibiotics once saved countless lives.However,nowadays,the abuse of antibiotics is extremely horrifying.From animal husbandry to medical treatment and food,the phenomenon of antibiotics abuse is ubiquitous.China has become the harder-hit area of antibiotics abuse.The abuse of antibiotics will lead to the production of multiple resistance and the release of endotoxin and the residues in livestock and poultry,which not only directly affect the safety and health of animal products,the production and economy of animal husbandry,but also greatly threaten the health and living environment of human beings.Therefore,Therefore,establishing a rapid and effective method to achieve effective detection of antibiotics in animal products is of major significance.Aptamer is achieved by SELEX,which embraces widely targets,high specificity and affinity.In this paper,aptamer is combined with the catalytic ability of AuNPs and Hemin to research on the detection of antibiotics.Some new methods of rapid,sensitive and specific detection were established,which provided a new idea for the detection of antibiotics in animal products.The main works of this article are as follows:(1)A novel colorimetric method for the detection of streptomycin(STR)aptamer is developed based on the peroxidase-like activity of gold nanoparticles(AuNPs)and aptamer.The detection system with and without streptomycin was characterized by transmission electron microscopy(TEM).To achieve a higher level of sensitivity,several key parameters of the proposed method such as pH,concentrations of STR1 aptamer and AuNPs,and incubation and reaction temperature have been investigated.Under optimal conditions,the proposed method can detect STR in a linear range from0.1 ?M to 0.5 ?M with a limit of detection(LOD)as low as 86 nM and exhibits good selectivity.Moreover,further studies also validate the applicability of the proposed method in milk samples with the recovery rate ranging from 90.8% to 98.9%.(2)A simple colorimetric method for detection of tetracycline(TET)was developed based on the enhanced peroxidase-like activity of hemin and aptamer.Toachieve a higher level of sensitivity,several key parameters of the proposed method such as pH,concentrations of Quadruplex aptamer and Hemin have been investigated.Under optimal conditions,the proposed method can detect TET in a linear range from10 ?M to 1000 ?M with a limit of detection(LOD)as low as 3.3 nM and exhibits good selectivity.Moreover,further studies also validate the applicability of the proposed method in milk samples with the recovery rate ranging from 94% to 99%.In conclusion,this paper is based on AuNPs and hemin as signal output carrier and aptamer.Thus,some sensitive,rapid,specific and legible to the naked eye method for antibiotic detection was established.And these established methods were simple and reliable,do not require complex molecular modification and expensive instrument,which could be applied to the antibiotic detection of the actual samples.Moreover,the method established in this paper is widely applicable,and could be applied to the detection of other biological environmental substances through the replacement of the aptamers used in above methods.