Determination of Aflatoxin B1 by Lateral Flow Assay Based on Molecule Beacon/Fluorescent Microsphere

KeyWord:aflatoxin B1  molecule beacon£¨MB£©  fluorescent microsphere£¨FM£©  lateral flow assay  quantitative analysis

Abstract:

      A new method was proposed for the determination of aflatoxin B1£¨AFB1£© by lateral flow assay based on molecule beacon£¨MB£©/fluorescent microsphere£¨FM£©.A MB containing AFB1 aptamer conjugated with FM,which was coated on the conjugate pad of a strip.A sequence containing adenine£¨A£© was coated on the nitrocellulose membrane£¨NCM£© at the test line,and another sequence complementing with AFB1 aptamer was coated on the control line.In the presence of AFB1,the specific combination of AFB1 and aptamer-FM led to the broken off of the double strand in MB.Then,the complex of AFB1/aptamer-FM was captured at the test line,and the excess MB/FM were captured at the control line.The fluorescence was observed with a fluorescence detector,and the content of AFB1 was estimated by the ratio of fluorescence peaks of the test line£¨T£© and the control line£¨C£©.The results showed that there existed a good linear relationship between the ratio of fluorescence peaks and AFB1 in the range of 0.1-50 ¦Ìg/L with a limit of detection£¨S/N=3£© approximately 0.05 ¦Ìg/L.With a light signal ¡°off-on¡± procedure,this proposed method could provide a new way for the accurate determination of AFB1.