Development Of Immunochromatographic Strip Based On Colloidal Gold For The Multiresidue Detection Of Mycotoxin

Colloidal gold immunochromatographic rapid test strips (GlCA) to test mycotoxin including T-2 toxin , zearalenone were developed. The single residue test strip was supposed to detect one single mycotoxin ,and the multi residue test strip was supposed to test two mycotoxins simultaneously.By optimization, the best conditions of T-2 toxin colloidal gold immunochro-matograpgic rapid test strip were : the size of gold nanoparticle was 18 nm; the Millipore HF135s was selected as the nitrocellulose membrane ; the optimal amount of T-2-BSA was 0.37?g/strip, diluted by PBS buffer liquid ; and secondary antibody was diluted 40 times by PB buffer liquid ;12?g antibody was used to be labeled by 1mL gold nanoparticle, and the optimum of pH was 8.0 ; the gold nanoparticle labeling antibody would be diluted 6 times ; and glass fiber pad was treated with PBST which was also chosen as standard diluent ; the procedure would take 10 min , with consequences of limit of detection at 5?g/L,grain sample limit of detection at 30?g/kg; the specificity of the test strip was good without cross reaction with other mycotoxins.The best conditions of ZEN colloidal gold immunochro-matograpgic rapid test strip was : the optimal size of gold nanoparticle was 18 nm; the Millipore HF135s was selected as the nitrocellulose membrane ; the optimal amount of ZEN-OVA was 0.3?g/strip, diluted by PBS buffer liquid ; secondary antibody was diluted 20 times by PB buffer liquid ; 24?g antibody was used to be labeled by 1mL gold nanoparticle, and the optimum of pH was 8.0 ; the gold nanoparticle labeling antibody would be diluted 6 times.The limit of detection was 10?g/L, and grain sample limit of detection is 60 ?g/kg .As for multi residue colloidal gold immunochro-matograpgic rapid test strip, the optimal conditions were : the size of gold nanoparticle and nitrocellulose membrane were the same as the single residue ones . antibodies would be labeled by gold nanoparticle separately , and reconstitution fluid mixture would be painted at the glass fiber pad by 30?L/cm . the amount of antibodies and pH were the same as single residue ones . some BSA was necessary when gold nanoparticle labeled antibody, 40?L would be needed for ZEN antibody in this study , and 20?L for T-2 antibody ,as usual . secondary antibody would be coated at the top of visible range by 30 fold dilution with PB buffer , and T-2-BSA was the next one , the last one was ZEN-OVA . both of the coating antigens were diluted by PBS buffer . And the other conditions and limit of detection show no differences from single residue ones .