Doxycycline Based On Molecular Imprinting Technique Study On SPR Detection

As the second-generation tetracycline broad-spectrum antibiotics,Doxycycline（DC）is widely used in animal husbandry and aquaculture because of its low price and stable properties.However,the abuse of DC will lead to its residue in water environment and animal-derived food,thus causing harm to human health.Therefore,the detection method of DC has become a research hotspot in recent years.At present,the main DC detection methods include chemiluminescence,high performance liquid chromatography,microbial method and so on.However,the content of DC in the water body is low,and the composition of the matrix is relatively complex.These detection methods all have disadvantages such as low sensitivity and complicated process,so it is necessary to develop a rapid,accurate and simple detection method.In this study,Molecularly Imprinted Films（MIF）are generated by in-situ photopolymerization directly on the traditional Surface Plasmon Resonance（SPR）sensor chip.Molecular Imprinting Technique（MIT）and SPR sensing technology were combined to develop a detection method for trace DC.First,Molecularly Imprinted Polymers（MIP）for DC have been prepared by thermal polymerization.The MIP was characterized by infrared spectroscopy,SEM and other methods,and the influence of adsorption time and concentration on the adsorption properties of DC was investigated.The addition ratio of each component in polymer synthesis was optimized by adsorption performance experiment.The experiment showed that when the addition amount of template molecule DC and functional monomers acrylamide and iconic acid were 0.4,4 and 3mmol,and the crosslinking degree was 4wt,the adsorption capacity of synthesized MIP for DC was the maximum.By comparing the adsorption of DC by MIP with other drugs,the separation factor of DC reached 3.49,which was much higher than that of other substrates,indicating its specific adsorption ability for DC drug molecules.Further,in this study,DC molecularly imprinted polymer film was assembled on SPR gold film by in-situ photopolymerization method to prepare MIT-SPR sensor chip,and SPR detection of DC drugs in aqueous solution was carried out.The results showed that the response signal of this method to DC drugs was significantly better than that of other interfering drugs,indicating that this method has good specificity for the detection of DC drugs.The detection limit of DC can reach10^-6μg/m L,and the linear range can reach 10^-6～10μg/m L.Compared with the current common detection methods,the DC drug detection method developed in this paper has better detection specificity,lower detection limit and larger detection linear range.