Visual Immunochromatographic Study Based On Two Novel Nanomaterials

Immunochromatographic assay(ICA)is a mature technology that is well suited for point-of-care and on-site detection.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,animal medicine,forensic determination and other fields of testing.Screening new markers and quantitative detection have always been the focus of immunochromatography research.In this study,the composite materials of blue SiNPs and Au@Pt were applied to the rapid detection of immunochromatography,and HBsAg was used as a model to construct an immunochromatographic quantitative detection method combining composite materials and Image J;In order to make it easier and cheaper to manufacture Immunochromatographic strips,we developed a new probe(ultramarine blue nanoparticles),RAC and HBsAg as research models,respectively,the construction of small molecules and protein detection,have a good detection effect.This paper has carried out the following parts:1.Au@Pt/blue SiNPs composite as probe of immunochromatographic assay for HBsAg detectionIn this article,a sensitive,visual and quantitative immunochromatographic assay(ICA)was described by using novel Au@Pt-decorated blue silica nanoparticles composite(Au@Pt/blue SiNPs)as probe.The Au@Pt/blue SiNPs were prepared by using in-situ synthesis methods,in which Au@Pt synthesized on the surface of blue SiNPs.Anti HBsAg mAb1 was conjugated with Au@Pt/blue SiNPs,due to the convenient surface modification and biocompatibility of Au@Pt,which were used as labels for ICA.The results were qualitatively analyzed by the naked eyes and quantitatively analyzed by the combination of a camera and Image J software,eliminating any lab equipment.The sensitivity of the Au@Pt/blue SiNPs based ICA was lowered 20 times and 10 times comparing with blue silica nanoparticles(blue SiNPs)and gold nanoparticles(GNPs)as probe,respectively.Under optimal conditions,a linear relationship between the color intensity and HBsAg over the range of 0.5~10 ng/mL was achieved,and the detection limit was estimated to be 0.13 ng/mL(S/N=3).The Au@Pt/blue SiNPs based ICA,thus,offered a sensitive method for rapidly detecting HBsAg.This nanocomposite label-based ICA is easily developed to be a universal signal amplification technique and applied to detection of other protein biomarkers.2.Ultramarine blue nanoparticles based immunochromatographic competive assay for rapid detection of RACA novel immunochromatographic assay(ICA)using ultramarine blue nanoparticles as label was developed for rapid detection of RAC.Ultramarine blue nanoparticles were separated from ultramarine blue industrial product by centrifugation.The polyacrylic acid(PAA)was used to modify the carboxyl group on the surface of ultramarine blue nanoparticles.RAC was selected as the model analyte for competitive ICA.Under appropriate conditions,the ultramarine blue nanoparticles-based ICA was developed to screen for RAC detection by naked eyes at cut-off values of 2 ng/mL,2 ng/mL and 1 ng/mL in phosphate buffered saline,feed and pork,respectively.The ultramarine blue nanoparticles-based immunoassay system has no cross activity with other nonspecific structural analogs.The results showed that ultramarine blue nanoparticles are promising to be alternative visible labels for the ICA strip.3.A immunochromatographic sandwich assay using ultramarine blue nanoparticles as visible label for quantitative detection of HBsAgFurther research on the novel visual probe ultramarine blue nanoparticles was carried out to construct a quantitative immunochromatography sandwich method using HBsAg as a detection model.The anti-HBsAg mAb1 was modified on ultramarine blue nanoparticles by EDC/NHS activation of the carboxyl groups.In the presence of HBsAg,the immune ultramarine blue nanoparticles were bound on test line zone and forming a blue line on ICA strip which was directly readout by naked eye and quantitatively measured by Image J software.Under optimal conditions,the color depth of test line was linearly correlated with the concentration of HBsAg in concentration range from 1 to 50 ng/mL.The calibration equation was y=385.796+97.2298x(R~2=0.9872),with limit of detection(LOD)of 0.37ng/mL(S/N=3).Thus,a new ultramarine blue nanoparticles-based ICA for quantitative detection of HBsAg was establish.In summary,this paper focuses on the preparation of visual nanomarkers and their applications in immunochromatography.Each of the constructed models demonstrates its unique advantages and has good sensitivity,specificity and stability.However,there are also their own shortcomings that require continuous research and improvement.