A Dual‐Emission Fluorescent Aptasensor Based on MXene ‐ Ti 3 C 2 T X / MoS 2 Composites for the Simultaneous Detection of Aflatoxin B1 and Ochratoxin A

A dual‐emission fluorescent aptasensor was developed for the rapid and simultaneous determination of aflatoxin B1 (AFB1) and ochratoxin A (OTA) in food samples. The platform integration relies on a MXene‐Ti 3 C 2 T X /MoS 2 composite quencher paired with two aptamer‐functionalized gold nanoclusters (AuNCs‐Apt) emitting at 525 and 630 nm. The MXene‐Ti 3 C 2 T X /MoS 2 composite exhibited higher quenching performance than either individual component. Furthermore, the introduction of Mn 2+ substantially enhanced the ΔF/F 0 from 3.45 and 4.35 to 7.00 and 10.68, which was attributed to the reduced electrostatic repulsion and facilitated probe adsorption. Under the optimized conditions, the proposed aptasensor exhibited linear detection ranges of 0.05–200 ng/mL for both OTA and AFB1, with limits of detection of 15.7 pg/mL and 8.6 pg/mL, respectively. The assay could be completed within 40 min without complicated separation procedures. In addition, the sensor demonstrated high selectivity, repeatability, and reproducibility. In individual target assays, recoveries of 94.1%–108.0% were obtained in spiked red wine and corn flour samples, and the analytical results agreed well with certified reference values. Furthermore, analysis of mixed OTA/AFB1 samples with varying target ratios yielded acceptable recoveries of 94.5%–111.0%, confirming independent and interference‐free dual‐target quantification. Compared with previously reported methods, the developed platform combines simultaneous dual‐target detection, a broad linear range, low detection limits, and a relatively short assay time within a single assay. These results indicate that the proposed aptasensor is a useful tool for rapid multiplex mycotoxin monitoring and food safety analysis.