Study On The Detection Of Ketamine And Amphetamine Based On SERS Competitive Immunoassay

Both Ketamine（KET）and Amphetamine（AMP）are one of the main drugs abused in our country.Long-term drug abuse can cause a series of toxic side effects such as confusion of consciousness and cognitive dysfunction.In severe cases,it can even cause serious physical and mental damage,and pose a threat to public safety.Therefore,it is imperative to carry out research on detection methods of ketamine and amphetamine content in human body.This study aims to establish a simple,rapid and highly sensitive single-and dual-index combined quantitative detection method for ketamine and amphetamine,which provides a more favorable scientific basis for the prevention and control of drug abuse and the identification and monitoring of drug users.This study is based on Surface-enhanced Raman Scattering（SERS）,using calf serum as a matrix sample,and labeling monoclonal antibodies on gold core silver shell nanoparticles embedded with Raman reporter molecules as the detection substrate,and the labeled antigen is attached to the carboxyl magnetic beads.Using the principle of competitive immunoassay,the test antigen competes with the labeled antigen for the monoclonal antibody labeled on the gold-core silver-shell nanoparticles.After immune reaction,the magnetic beads were enriched,and the quantitative detection of the antigens was realized by detecting the Raman signal at the Raman characteristic peak on the magnetic beads.The results showed that:（1）Within the concentration range of 0.0-100.0 ng/m L,the KET concentration has a good correlation with Raman signal（r=0.9972）,the limit of detection is2.83 ng/m L;the spike recovery rate is between 95.1%-101.2%;the precision test results show that the intra-assay and inter-assay concentration variation coefficient of the three batches of reagents is between 4.3%-20.8%;there is no cross-reaction with other high-concentration drugs;common interfering substances and anticoagulants in serum have no significant effect on the experimental results;the precision and accuracy of the established method meet the requirements of serum sample analysis,and it has good selectivity.（2）Within the concentration range of 0.0-200.0 ng/m L,AMP concentration has a good correlation with Raman signal（r=0.9994）,the limit of detection is 2.28 ng/m L;the spike recovery rate is between 88.9%-111.0%;the precision test results show that the intra-assay and inter-assay concentration variation coefficient of the three batches of reagents is between2.1%-18.4%;there is no cross-reaction with other high-concentration drugs;common interfering substances and anticoagulants in serum have no significant effect on the experimental results;the precision and accuracy of the established method meet the requirements of serum sample analysis,and it has good selectivity.（3）Dual-index combined quantitative detection of KET and AMP.KET and AMP have good correlation with Raman signals in the concentration range of 0.0-60.0 ng/m L and0.0-200.0 ng/m L respectively(r_KET=0.9965,r_AMP=0.9998),the limits of detection are 1.64 and2.44 ng/m L,and the spike recovery rate is between 80-115%;the precision test results show that the intra-assay and inter-assay concentration variation coefficient of the three batches of reagents is about 15%;there is no cross-reaction with other high-concentration drugs;common interfering substances and anticoagulants in the serum have no significant effect on the experimental results;two methods,SERS and liquid chromatography-tandem mass spectrometry（LC-MS/MS）used by the industry standard were used to detect 27 KET and AMP mixed standard samples and compare the results.For KET detection,there was no statistical difference between the two methods（t=-0.768,p=0.446>0.05）,and the correlation was good（r=0.9813）;For AMP detection,the two methods had no statistical difference（t=-0.436,p=0.665>0.05）,the correlation is good（0.9905）;the precision and accuracy of the established joint detection method meet the requirements of serum sample analysis,and it has good selectivity.Compared with industry standard methods,it has more convenient advantages.In this study,a portable Raman spectrometer and SERS technology were used to successfully establish a quantitative detection method for ketamine and amphetamine with simple operation,high sensitivity and good specificity,and a dual-index simultaneous quantitative detection was realized.This rapid and sensitive detection provides a new technical reference for more convenient drug detection.Compared with other detection methods that have been reported,this study does not require complicated sample pre-processing procedures.The labeled antigen can be directly connected to the carboxyl magnetic beads,and the laboratory environment and the technical requirements of the testing personnel are relatively low,and immediate on-site testing at the grassroots level can be further carried out.