Development of an ultrasensitive aptasensor for the detection of aflatoxin B1

Contamination of feed and food by aflatoxin B-1 (AFB(1)), one of the most toxic of the mycotoxins, is a global concern. To prevent food safety scares, and avoid subsequent economic losses due to the recall of contaminated items, methods for the rapid, sensitive and specific detection of AFB(1) at trace levels are much in demand. In this work, a simple, ultrasensitive, and reliable aptasensor is described for the detection of AFB(1). An AFB(1) aptamer was used as a molecular recognition probe, while its complementary DNA played a role as a signal generator for amplification by real-time quantitative polymerase chain reaction (PCR). Under optimal conditions, a wide linear detection range (5.0 x 10(-5) to 5.0 ng mL(-1)) was achieved, with a high sensitivity (limit of detection (LOD)=25 fg mL(-1)). In addition, the proposed aptasensor exhibited excellent specificity for AFB(1) compared with eight other mycotoxins, with no obvious Ct value change. This aptasensor can also be used in quantifying AFB(1) levels in Chinese wildrye hay samples and infant rice cereal samples, demonstrating satisfactory recoveries in the range of 88-127% and 94-119%, respectively. This detection technique has a significant potential for high-throughput, quantitative determination of mycotoxin levels in a large range of feeds and foods. (C) 2014 Elsevier B.V. All rights reserved.