A novel aflatoxin B₁ biosensor is fabricated from a porous anodized alumina membrane modified with graphene oxide and an aptamer of aflatoxin B₁. Briefly, the aptamer is immobilized on the surface of the porous anodized alumina nanochannels by covalent bonding. Graphene oxide is then added to the surface by π-π stacking with the aptamer. The negative charge of the nanochannels is increased by the introduction of the negatively charged graphene oxide and the aptamer, which also cause steric hindrance. On the addition of aflatoxin B₁, graphene oxide is detached from the surface of the nanochannels due to the specific binding of aflatoxin B₁ to the aptamer. The flux of Fe(CN)₆³⁻ through the nanochannels is increased because the charge density and steric hindrance are reduced, resulting in an increased current response. The increase in current is proportional to the concentration of aflatoxin B₁. The detection limit of the proposed biosensor is about 0.13 ng/mL and the linear range is 1–20 ng/mL. Furthermore, this sensor has excellent selectivity towards aflatoxin B₁, offering the potential for a sensitive, simple and effective method for detecting mycotoxins.

一种新型的黄曲霉毒素B ₁生物传感器是由氧化石墨烯和黄曲霉毒素B ₁的适体修饰的多孔阳极氧化铝膜制成的。简而言之，适体通过共价键合固定在多孔阳极氧化铝纳米通道的表面上。然后通过与适体的π-π堆叠将氧化石墨烯添加至表面。纳米通道的负电荷通过引入带负电荷的氧化石墨烯和适体而增加，这也会引起空间位阻。在添加黄曲霉毒素B _1时，由于黄曲霉毒素B ₁与适体的特异性结合，氧化石墨烯从纳米通道的表面脱离。Fe（CN）₆ ³⁻的通量由于减少了电荷密度和位阻，增加了通过纳米通道的电流，从而导致电流响应增加。电流的增加与黄曲霉毒素B ₁的浓度成正比。拟议中的生物传感器的检出限约为0.13 ng / mL，线性范围为1–20 ng / mL。此外，该传感器对黄曲霉毒素B ₁具有极好的选择性，为检测霉菌毒素提供了一种灵敏，简单而有效的方法。