A self-calibrating ratio fluorescence aptamer sensor based on PCN-224 for the highly sensitive detection of alternariol in cereals

Alternariol (AOH) is an emerging mycotoxin widely found in agricultural products. It has drawn attention due to the potential health risks associated with long-term dietary exposure. Therefore, a ratiometric fluorescent aptamer sensor based on PCN-224 was developed. By combining the intrinsic fluorescence properties of PCN-224 with aptamer recognition, sensitive detection of AOH was achieved. PCN-224 served as both a fluorescence platform and a source of internal reference signals, enabling self-calibrated ratio analysis. Under optimal conditions, the sensor exhibited good linear response in the range of 0.001–500 ng/mL. The LOD was 0.449 pg/mL. It also exhibited good selectivity, stability, and reproducibility. This sensor has been successfully applied to the detection of AOH in cereal samples, demonstrating its reliability in the analysis of complex food matrices. This work provided an effective strategy for monitoring mycotoxins by combining MOF fluorescence regulation with aptamer recognition.