title: A nanoparticle-based bio-barcode assay for ultrasensitive detection of ricin toxin.
abstract: The ultrasensitive bio-barcode amplification assay (BCA) technique was developed for the specific detection of the A chain of ricin toxin. The target antigen A chain was first captured by gold nanoparticles (GNPs) coated with polyclonal antibodies. Magnetic microparticles (MMPs) coated with A chain monoclonal antibody were then added to form a sandwich immuno-complex. After the immuno-complex was formed, signal DNA annealed to DNA strands covalently bound to the GNPs were released by heating and characterized by PCR and real-time fluorescence PCR. A detection limit of 1fg/ml was measured for A chain, six orders of magnitude more sensitive than that of conventional antigen-capture ELISA. The coefficient of variation (CV) of intra-assay and inter-assay ranged from 3.39% to 6.84%. The BCA can detect the A chain in milk and water mimic samples. In the following work it is demonstrated that this assay is a highly sensitive method for the detection of ricin proteins that could be adapted to measure other proteins.
authors: Institute of Transfusion Medicine, The Academy of Military Medical Sciences, Beijing 100850, China.
authors: Hui-qiong
authors: HQ
authors: Yin
authors: Min-xian
authors: MX
authors: Jia
authors: Shu
authors: S
authors: Yang
authors: Sheng-qi
authors: SQ
authors: Wang
authors: Jin-gang
authors: JG
authors: Zhang
mesh_terms: D000941:Antigens / Q000032:analysis / Q000737:chemistry; D058893:DNA Barcoding, Taxonomic; D006046:Gold; D007118:Immunoassay / Q000379:methods*; D057230:Limit of Detection; D008280:Magnetics; D053768:Metal Nanoparticles; D010940:Plant Proteins / Q000032:analysis / Q000737:chemistry; D015203:Reproducibility of Results; D012276:Ricin / Q000032:analysis* / Q000737:chemistry
chemical_list: D000941:Antigens; D010940:Plant Proteins; D006046:Gold; D012276:Ricin