Nanomechanical label-free detection of aflatoxin B1 using a microcantilever

Aflatoxin B1 (AFB1), a hepatocarcinogen widely present in food and food materials, is highly dangerous to human health, and new sensitive methods to detect AFB1 are needed. Here, we developed a microcantilever-array-based immunosensor used in stress mode to detect AFB1 with the obvious advantages of a high sensitivity, rapidity, label-free, quantitative, and ability to be performed in real-time. The microcantilever was functionalized with a sulfhydrylated anti-AFB1 antibody, and an ELISA was used to validate the activity of the antibody on the microcantilever. Deflection of the microcantilever corresponding to different AFB1 concentrations was monitored in real-time. The detection limit of the microcantilever sensor in stress mode was lowered to 0.03 ng/mL for AFB1, which is a significant improvement in comparison with icELISA or a microcantilever sensor operated in dynamic mode. We also successfully detected AFB1 dissolved in a peanut solution. The microcantilever sensor in stress mode provides a new method for detecting extremely low concentrations of AFB1 and may have great potential for food quality control and public health protection.