Preparation And Application Of High SERS Performance Substrate For Detection Of Kanamycin Residues In Milk

The residue of antibiotics in milk and other agricultural and sideline products is mainly due to the unreasonable use of antibiotics in the process of raising livestock,and long-term ingestion of milk containing antibiotics will cause great harm to human body.The traditional methods of antibiotic analysis and detection have many problems such as high cost,long time and low sensitivity.Therefore,a fast,low cost and high detection efficiency analysis and detection means is needed.SERS technology has been widely used in various fields due to its advantages such as high sensitivity,non-destructive detection,short time consuming and good repeatability.In this paper,with the detection of antibiotic residues by SERS technology as the target,three kinds of silver based SERS substrates were prepared,and porous silicon-silver nanoparticle substrate with the optimal SERS performance was screened out to achieve rapid trace detection of kanamycin in milk.The main research contents of this paper are as follows:（1）Preparation,parameter optimization and characterization of three SERS substrates based on silver.Theβ-CD（cyclodextrin）-nano silver sol was prepared by sodium citrate reduction method,the porous silicon-silver nano dendrite substrate was prepared by one-step electrochemical anodizing method,and the porous silicon-silver nano particle substrate was prepared by improved dipping method,and its parameters were optimized and characterized.（2）Comparison of performance of three SERS substrates based on silver.Rhodamine 6G was used as the probe molecule to evaluate the performance of the three kinds of SERS substrates prepared above,and the best SERS performance base-porous silicon-silver nano particle was selected from three aspects of sensitivity,repeatability and time stability.（3）Application of kanamycin residue detection in milk based on SERS substrate of porous silicon-silver nano particle.Firstly,porous silicon-silver nano particle was used for SERS detection of kanamycin aqueous solution,and the detection limit of kanamycin aqueous solution was 10^-15 g/m L.Meanwhile,a series of concentration gradient kanamycin aqueous solution was fitted with the concentration and peak value,and the fitting result was as follows:y=-0.11334x+3.7962.R²=0.94531,showing a good linear correlation.Finally,milk was taken as the actual sample,and kanamycin was added after milk treatment to simulate the analysis and detection of kanamycin residues in real food.The experimental results show that the detection limit of kanamycin residue in milk is 10^-15 g/m L.The peak diagram of kanamycin in milk is fitted with the peak concentration and peak value.The fitting equation is as follows:y=-0.06869 x+4.18737,R²=0.98377.The recovery rate of this linear fitting equation is91.6%～112%,which proves that this substrate has a certain reliability in the detection of kanamycin residue in milk.In this study,not only the high SERS property base was prepared and screened,but also the trace detection of kanamycin residue in milk was realized by using it,which provided a new idea for the detection and analysis of kanamycin and also made a contribution to the detection of antibiotics by SERS technology.