Research On Immune Chromatographic Lateral Flow Strip For Detection Of Capsaicin In Edible Oil

As capsaicin itself has the characteristics of lipophilic,stable and high boiling point,it is difficult to separate from gutter oil,so it can be used as a specific indicator to identify whether cooking oil is gutter oil.Therefore,three different immunochromatographic test strip methods were established to detect capsaicin in edible oil:(1)establishment of a method for determination of capsaicin in edible oil by traditional immunoassay paperPrinciple of this method is to lateral chromatography and capillary antigen antibody immune recognition,the combination of antibody can be used by static adsorption and gold nanoparticles surface coupling,the C line in NC membrane fixed sheep rat resistance,resistance T online fixed capsaicin antigen,usually by NC membrane whether T line and C line color to judge the existence of the capsaicin in cooking oil,at the same time with gray scale scanning results combined with quantitative analysis to the content of capsaicin.On the basis of the feasibility study,the coupling amount,coupling p H,resuspended solution,sample pad treatment solution and sample dilution buffer were optimized to obtain the best experimental scheme and to detect the specificity and sensitivity of traditional capsaicin strips.Under the best experimental conditions,the content of capsaicin can be determined within 10 minutes.The sensitivity of visual observation strip is 100 ?g/L,and the linear range of standard curve detection is 10-100 ?g/L.(2)establishment of an improved method for determination of capsaicin in edible oil by immunoassay paperThis method is the basis of the traditional immune lateral chromatography test paper to detect general conjugates pad abandon,conjugates coupling product drop into 96-well plates of microporous freeze drying,the experiment on the freeze drying and sample liquid in the process of the incubation time optimization optimal experiment scheme,and optimize the gold nanoparticles and capsaicin antibody coupling,the selection of sealing fluid,the choice of suspension and 96 in the orifice microporous add quantity,sensitivity and the detection of freeze drying capsaicin strip.Under the best experimental conditions,the detection of capsaicin was completed within 15 min,and the sensitivity of naked eye observation was 10 ?g/L,which was 10 times higher than the traditional method.The linear range of the standard curve is 2.5 to 50 ?g/L.(3)establishment of a method for the determination of capsaicin in immunoassay paper labeled by time-resolved fluorescent microspheresThis method is based on the detection principle of the competition method,the immunochromatography test paper is established by using the time-resolved fluorescent microspheres to mark the capsaicin antibody,and the capsaicin in edible oil is detected quickly and accurately.The specific surface area of the time-resolved fluorescent microspheres is large,and a certain number of carboxyl functional groups are modified on the surface of the fluorescent microspheres,which can effectively couple the amino group on the surface of the protein or antibody with the carboxyl group on the surface of the fluorescent microspheres by covalent binding,thus improving the stability of the labeling processing.This method is to mark capsaicin monoclonal antibody on the surface of time-resolved fluorescent microspheres,fix capsaicin antigen on the T line of NC film,and fix sheep anti-mouse secondary antibody on the C line.It can be seen by naked eye whether the T line and C line on the NC film show color,so as to quantitatively analyze the content of capsaicin in edible oil.In this study,the coupling amount,the type of blocking agent,the type of suspension and the buffering liquid system of the fluorescent microspheres and capsaicin antibody were optimized to determine the optimal experimental parameters,and the specificity and sensitivity of the time-resolved fluorescent microspheres and capsaicin strips were detected.Under the optimal experimental conditions,the detection of capsaicin can be completed within 10 minutes,the sensitivity of direct visual observation is 20 ?g/L,and the linear detection range of the standard curve is 2.5-50 ?g/L.Therefore,it can be seen that the sensitivity and stability of the immunoassay paper based on time-resolved fluorescent microspheres labeled with antibodies are not inferior to that of traditional gold nanoparticles markers,which lays a certain foundation for the follow-up application of time-resolved fluorescent microspheres in immunoassay paper.