Indirect competitive immunoassay for detection of aflatoxin B1 in corn and nut products using the array biosensor

Because of the potential health risks of aflatoxin B-1 (AFB(1)), it is essential to monitor the level of this mycotoxin in a variety of foods. An indirect competitive immunoassay has been developed using the NRL array biosensor, offering rapid, sensitive detection and quantification of AFB(1) in buffer, corn and nut products. AFB(1)-spiked foods were extracted with methanol and Cy5-anti-AFB(1) added to the resulting sample. The extracted sample/antibody mix was passed over a waveguide surface patterned with immobilized AFB1. The resulting fluorescence signal decreased as the concentration of AFB(1) in the sample increased. The limit of detection for AFB(1) in buffer, 0.3 ng/ml, was found to increase to between 1.5 and 5.1 ng/g and 0.6 and 1.4 ng/g when measured in various corn and nut products, respectively. (c) 2005 Elsevier B.V. All rights reserved.