Detection Of Tetracycline Antibiotic Residue In Food By Fluorescence And Chemiluminescence Methods Based On The Enzyme-like Activity Of Ferroferric Oxide

Antibiotics is one of the most widely utilized drugs,which play a critical role in the field of clinical treatment and animal husbandry production.However,the abuse of antibiotics becoming more and more serious,which bring a serious threat to human health and the ecological environment.Therefore,it is very important to develop a simple,fast and sensitive method for antibiotics detection.In this paper,a fluorescence assay method and chemiluminescence assay method that based on the catalytic ability of Ferric oxide nanoparticles(Fe3O4 NPs)are established for the detection of three tetracycline antibiotics(TCs),and applied in the detection of TCs in real samples include milk,egg and honey.The main contents are as follows:(1)The fluorescence assay was developed for the detection of TCsThe Fe3O4 NPs were prepared by solvothermal method.Based on the enzyme-like activity of Fe3O4 NPs,a fluorescence detection method for TCs was constructed by using Rhodamine 6G fluorescent dye(Rh6G),Hydrogen peroxide(H2O2),and Potassium iodide(KI).The detection principle is Fe3O4 NPs can catalyze the decomposition of H2O2 into hydroxyl radicals(·OH).Iodide ions(I-)can be oxidized into iodine molecules(I2)by ·OH,I-can combine with I2 to generate iodine tri-negative ion(I3-),I3-can react with Rh6G to form a polymer(Rh6G?I3)n,and(Rh6G-I3)n has no fluorescence properties,so the fluorescence of Rh6G could be quenched.After the TCs added into the reaction system,the enzyme-like activity of Fe3O4 NPs would be enhanced,which would intensify the fluorescence quench of Rh6G.Under optimized conditions,a good linear relationship was obtained.The concentration of oxytetracycline(OTC)had a good linear relationship with the fluorescence intensity in the range of 40?2400 nmol/L.The regression equation was F=9.4005-0.0031 X C(coefficient of determination R2=0.9967),F was The fluorescence intensity of Rh6G at 557 nm,C was the concentration of OTC,and the limit of detection(LOD)is 20 nmol/L.The concentration of chlortetracycline(CTC)had a good linear relationship with the fluorescence intensity in the range of 50?1500 nmol/L.The regression equation was F=9.9138-0.0056xC(R2=0.9945),LOD was 40 nmol/L.The concentration of tetracycline(TC)had a good linear relationship with the fluorescence intensity in the range of 30?1800 nmol/L.The regression equation was F=9.2629-0.0042×C(R2=0.9924),LOD was 10 nmol/L.The results of precision and specific experiments showed that the fluorescence analysis method was stable and had good specificity for TCs.And this method could be used for the detection of TCs in milk,eggs and honey.(2)The Chemiluminescence assay was developed for the detection of TCsBased on the enzyme-like activity of Fe3O4 NPs,a Fe3O4 NPs-luminol-H2O2 chemiluminescence system was established for the detection of TCs.Fe3O4 NPs can catalyze the reaction between luminol and H2O2 due to its enzymatic activity.After the TCs was added,the catalytic ability of Fe3O4 NPs was enhanced,and the chemiluminescence intensity of this system was also enhanced.A standard curve was obtained by optimizing various experimental factors.The concentration of OTC had a good linear relationship with the chemiluminescence intensity of the system in the range of 10?2800 nmol/L.The regression equation was RLU=8.4831×C+83232.0105(R2=0.9872),RLU was The chemiluminescence intensity of this system,C was the concentration of OTC,LOD is 6 nmol/L.The concentration of CTC had a good linear relationship with the chemiluminescence intensity of the system in the range of 5?2100 nmol/L.The regression equation was RLU=12.0893×C+77824.0576(R2=0.9845),LOD was 2 nmol/L.The concentration of TC had a good linear relationship with the chemiluminescence intensity of the system in the range of 10?2400 nmol/L.The regression equation was RLU=13.3581×C+75627.4275(R2=0.9902),LOD was 4 nmol/L.The precision experiments and specific experiments showed that the chemiluminescence analysis method was stable and has good specificity for TCs.And this method could also be used for the detection of TCs in milk,eggs and honey.(3)Comparison of the detection results between fluorescence method and chemiluminescence method and high performance liquid chromatography methodIn order to evaluate the two analytical methods that established in this study.This article also refers to the relevant regulations of the Chinese national standard,took advantage of the high performance liquid chromatography to detect TCs,and the detection results of three methods was compared.The indicators for comparison include the linear range,limit of detection,precision and recovery of each method.The results showed that all three methods can detect TCs in actual samples.The fluorescence method and the chemiluminescence method take on high sensitivity and high recovery and the HPLC method has good precision and high stability.