Study On Encoding Quantitative Immunochromatographic Assay Based On Colored Sinps

Immunochromatographic assay(ICA)is a mature technology.The method has the advantages of simple operation,rapid detection and low price.No instrument equipment and professional technicians are required in the assay,and the results are judged intuitively and reliably.ICA is widely used in entry and exit inspection and quarantine,environmental monitoring,food quality and safety,medical testing and other fields of testing.At present,commercial immunochromatography is mainly based on single substance detection and qualitative detection.However,there are two or more analytes in the actual detection,so it is very necessary to develop a multiple immunochromatographic assay.In this study,the color silica nanoparticles(colored SiNPs)independently developed by our laboratory and software Image J were applied to improve the immunochromatographic assay:we realize the quantitative detection of hepatitis B surface antigen(HBsAg);Clebuterol(CLE)and Ractopamine(RAC)were used as model samples to construct a two-substance encoding recognition and double quantitative immunochromatographicassay,and good detection results were obtained.The study is divided into the following three parts:1.Quantitative immunochromatographic detection of HBsAg based on red SiNPsIn order to improve immunochromatographic assay and achieve quantitative detection,we have constructed an immunochromatographic sandwich method using red silica nanospheres(red SiNPs)as Ab markers and HBsAg as a detection model in the study.Red SiNPs-COOH generated by carboxyl-activated red SiNPs can increase the coupling strength and coupling rate of anti-HBsAg monoclonal antibody(anti-HBsAg mAb)rich in-NH2,and make immunoprobe for HBsAg detection.The HBsAg concentration had a linear relationship in the range of 5～500 ng/mL.The linear equation was y=370.6118+9.6673x(R2=0.9962),and the detection limit is 0.97 ng/mL.This study provides a simple and quantitative method for clinical diagnosis and food safety analysis.2.Red and blue silica nanoparticles based immunochromatographic assay for multiplex visible and encoding detection of clenbuterol and ractopamine with a single test lineIn order to improve the immunochromatography and achieve simultaneous detection of two substances to be tested,we have prepared and encoded red SiNPs and blue silica nanoparticles(blue SiNPs),activated to make immunolabeled probes,and improved immunochromatographic assay to recognize CLE and RAC in a single T-line by competitive method in the study.Under the optimal detection conditions,the detection limit value of CLE is 3 ng/mL,and the detection limit value of RAC is 2 ng/mL.There is no cross-reaction with similar drugs.It can be seen that the immunochromatographic assay based on red and blue SiNPs can encode and identify CLE and RAC to achieve double detection.The method has the advantages of fast,simple,economical and accurate,and is convenient for popularization and application.3.Multiplex immunochromatographic assay conbined with blue and purple silica nanoparticles for encoding and quantitative detection of RAC and CLEIn order to improve the quantitative detection of two kinds of harmful substances in foods by improved immunochromatographyic assay,blue SiNPs and purple silicon nanospheres(purple SiNPs)were prepared and activated to prepare immunolabeled probes:anti-CLE mAb-blue SiNPs and anti-RAC mAb-purple SiNPs were tested for CLE and RAC.The CLE and RAC concentration had a linear relationship in the range of 0.5～8 ng/mL and 0.5～8 ng/mL,the linear equation were y=5617.2-5486.4x(R2=0.952)and y=2062.3-1961.3x(R2=0.924),and the detection limits of the two substances were 0.172 ng/mL(CLE)and 0.065 ng/mL(RAC).The method can simultaneously detect two harmful substances and carry out quantitative analysis,can develop into a general analytical detection system by replacing the antigen and antibody,and provide new ideas and methods for food safety analysis.The above studies show that the three immunochromatographic methods modified by immunological colored SiNPs and Image J analysis software can achieve qualitative and quantitative detection of HBsAg and CLE/RAC,provide research models for food safety analysis and in vitro diagnosis,and provide theoretical basis for on-site testing and application.