Construction of an aflatoxin aptamer sensor based on a DNA nanoprism structure

Aflatoxin B1 (AFB1) is a group of heterocyclic aromatic hydrocarbon secondary metabolites, which are the most toxic among the known fungal toxins. Therefore, it becomes particularly important to develop sensitive, accurate, rapid and simple methods for the detection of AFB1. In this work, a method of constructing aflatoxin aptasensor with black phosphorus nano sheet loaded with gold nanoparticles as electrode modification material, Ce-metal organic framework (MOF) material as signal label and prism DNA nano structure modified electrode as recognition interface is proposed. The hybridization between prism DNA and primer probe was used to trigger rolling circle amplification (RCA) on the electrode surface, and then the complementary chain modified with Au NPs@Ce-MOF is bound to the amplification chain to provide electrochemical signals. In the range of 0.024-100 ng mL^-1, the response current showed a good linear relationship with the logarithm of aflatoxin concentration, the linear equation was I = 6.4181 lg c + 11.975 with the linear correlation coefficient of 0.9973, and the detection limit was 1.48 pg mL^-1 (S/N = 3).