Aptasensor development for T-2 toxin detection utilizing a dual signal amplification strategy: Synergistic effects of bimetallic oxide (Ce-In)Ox and COFTAPB-DMTP

The innovative bimetallic oxide, (Ce-In)Ox, derived from a (Ce-In)-metal organic framework (MOF), has been meticulously characterized to unveil its superior electrochemical properties. Harnessing the synergistic "dual-signal amplification" effect brought about by the collaborative actions of (Ce-In)Ox and COFTAPB-DMTP@Au-Apt (TAPB, 1,3,5-tris(4-aminopheny) benzene; DMTP, 2,5-dimethoxybenzene-1,4-dicarboxaldehyde; COF, covalent organic framework; Apt, aptamer), we developed an aptasensor. This aptasensor utilized methylene blue (MB) as its electrochemical signal probe, demonstrating unparalleled performance. Upon the presence of T-2 toxin, the aptamer undergoes a conformational change, leading to the detachment of MB from both the DNA duplex and the COF, thereby causing distinguishable electrochemical variations. Under the optimal conditions, the aptasensor achieved a detection limit as low as 7.6 × 10-8 ng mL-1 (S/N = 3) and proved proficient across a concentration range from 5.0 × 10-7 ng mL-1 to 5.0 ng mL-1. The robustness and reliability of this aptasensor were further validated using authentic crop samples, highlighting its immense potential in food safety and quality control applications.