Figure 6.

Detection principle of a colorimetric biosensor to detect AFB1 and OTA. Formerly, the two platforms of Fe₃O₄/GO and TP-GO and Fe₃O₄@Au and Au NPs were formed through the combination of an AFB1 aptamer and the complementary strands of an OTA aptamer and probe, respectively. The absence and presence of both AFB1 and OTA will result in platform separation and a colorless supernatant. The addition of an alkaline solution to magnetically separated solids and the usage of Au NPs in the supernatant, on the other hand, results in a dark blue-colored solution. Reprinted from [134] with permission from Elsevier.