Development And Application Of Fluorescent And Visual Method For Veterinary Drug Residues Detection

Fluorescence detection method has been widely used in the field of food analysis due to its advantages of rapidness,sensitiveness,rich fluorescence signals and easy operation.In this paper,malachite green,sulfamerazine and tetracycline were used as the detection objects,respectively.Metal-organic framework materials(MOF)and their composite materials were used as fluorescence probes to establish rapid,sensitive and reliable fluorescence and visualization detection methods.The main contents are as follows:(1)Establishment and application of fluorescent and visual method for malachite green and sulfamerazine detection.Firstly,a bimetallic organic framework(Tb_0.6Eu_0.4-MOF)was successfully synthesized at room temperature.Based on the mechanism of inner filter effect,a fluorescence detection method for malachite green(MG)and sulfamerazine(SMZ)was established by using Tb_0.6Eu_0.4-MOF as the fluorescence probe.Under the optimized experimental conditions,the detection limits for malachite green and sulfamerazine were 1.1?M and 0.1?M,respectively.The method was applied for quantitative determination of malachite green and sulfamerazine in fish samples with satisfactory recoveries of101.45%?116.63%and 92.87%?107.90%,respectively.Moreover,under 254 nm UV lamp irradiation,the color of the fluorescent probe changed from orange to green with the increasing concentration of malachite green.However,with the increasing concentration of sulfamerazine,the color of the fluorescent Tb_0.6Eu_0.4-MOF was gradually quenched.The visual detection of malachite green and sulfamerazine could be achieved through calculating the relationship between RGB values and the concentrations of the corresponding veterinary drug residues.(2)Antenna effect induced fluorescent sensing for tetracycline and its application.A fluorescent and visual detection method for tetracycline was developed for tetracycline detection in milk by using UIO-66-NH₂/Eu³⁺as the fluorescence probe based on the antenna effect mechanism.Under the optimal experimental conditions,the linear range of the developed method was 0.5?200?M,and the detection limit was 0.2?M.The method was applied to the determination of tetracycline in milk samples with good recoveries of 97.94%?101.30%and good relative standard deviations of 0.76%?2.34%.In addition,the fluorescence test paper based on UIO-66-NH₂/Eu³⁺was prepared.The color of the test paper changed from blue to red with the increasing concentration of tetracycline under the irradiation of 365 nm UV lamp,which provided a rapid,simple,sensitive and visual method for tetracycline detection.(3)A portable smartphone-assisted ratiometric fluorescence sensor for intelligent and visual detection of malachite green.A fluorescent method for malachite green detection was established by using Al-MOF nanosheets and Rhodamine B(Rh B)as the fluorescent probes based on the mechanism of inner filter effect.The developed ratiometric fluorescent sensor allowed sensitive and selective detection of MG with a good linear relationship in the range of0.5?200?g/m L.The Quantitative linear range is from 5.3?g/m L to 200?g/m L.The limit of detection(LOD)and limit of quantification(LOQ)were calculated to be 1.6?g/m L and 5.3?g/m L,respectively.The practicability of the proposed method was verified by high performance liquid chromatography(HPLC).Moreover,portable fluorescent test papers were fabricated.And then,the intelligent detection of malachite green was achieved through the combination of via a smartphone application(APP).This integration of smartphones and fluorescent test papers possessed the advantages of low-cost and time-saving,providing a promising analytical method for the qualitative discernment and semi-quantitative analysis of MG on-site.