Detection of AFB1 in Nuts by a Nanoparticle-based Bio-Barcode Assay
Article
Figures
Metrics
Preview PDF
Reference
Related
Cited by
Materials
Abstract:
Gold nanoparticle probes (NP) were prepared using gold (Au) nanoparticles, AFB1 polyclonal antibodies, a complementary gold nanoparticle probe, and barcode DNA, and was characterized after purification using transmission electron microscopy (TEM), ultraviolet-visible (UV-vis) spectroscopy, and concentration measurement. NPs were coupled with AFB1 monoclonal antibody-modified magnetic microspheres (MMPs) through an antigen-antibody interaction to yield NP-AFB1-MMP sandwich compounds. Fluorescence quantitative-polymerase chain reaction (FQ-PCR) was employed to detect the bio-barcode DNA that was released under high temperature and low salt conditions. A bio-barcode assay for detecting AFB1 was established by investigating the linear correlation between the number of the cycles required for the fluorescence signal in each tube to reach the set threshold value after the reaction, and the number of the corresponding initial template copies, and methodological evaluation was conducted on the detection system. The results indicated that the method established in this experiment is rapid, sensitive, and highly specific. A significant linear relationship was observed between the number of the cycles in each template and the logarithm of the number of initial copies of this template (y = –2.9054x + 54.581, r=0.9991). The detection sensitivity limit was about 10-8 ng/mL, much more sensitive than the limit of an enzyme-linked immunosorbent assay (ELISA). The intra- and inter-assay CV (coefficient of variation) values of FQ-PCR were less than 5%, indicating satisfactory accuracy. The established bio-barcode assay (BCA) was used to conduct a crossover experiment on compounds with similar structures, and the results showed a good specificity. This method can be used to determine trace amounts of AFB1 in peanuts, cashews, and other nuts．
