A biosensor method based on surfactant-mediated surface droplet evaporation for the detection of Aflatoxin B₁

Aflatoxin B₁ (AFB₁) is a common mycotoxin that is of significant global concern due to its impact on food safety. Herein, we innovatively develop a sensing platform to detect AFB₁ based on evaporation of surfactant solutions on the hydrophobic surface, resulting in dried patterns with varied sizes. The surfactant CTAB solution produces a relatively large dried pattern due to the surface wetting. However, the reduction in the dried pattern size is found when the mixture of CTAB and AFB₁ aptamer is tested, because the formation of CTAB/aptamer complex. Moreover, the dried pattern size of the mixture of CTAB, aptamer, and AFB₁ increases due to the specific binding of AFB₁ to its aptamer. Using this innovative strategy, the AFB₁ detection can be fulfilled with a detection limit of 0.77 pg/mL. As a simple, convenient, inexpensive, and label-free method, the surfactant-mediated surface droplet evaporation-based biosensor is very promising for various potential applications.